java final

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One byte has ________ bits

8 bits

Every letter in a Java keyword is in lowercase? A. true B. false

Suppose a Scanner object is created as follows: Scanner input = new Scanner(System.in); What method do you use to read a real number? A. input.nextDouble(); B. input.nextdouble(); C. input.double(); D. input.Double()

Suppose your method does not return any value, which of the following keywords can be used as a return type? A. void B. int C. double D. public E. None of the above

To obtain the arc sine of 0.5, use _______. A. Math.asin(0.5) B. Math.asin(Math.toDegrees(0.5)) C. Math.sin(Math.toRadians(0.5)) D. Math.sin(0.5)

What exception type does the following program throw? public class Test { public static void main(String[] args) { System.out.println(1 / 0); } } A. ArithmeticException B. ArrayIndexOutOfBoundsException C. StringIndexOutOfBoundsException D. ClassCastException E. No exception

What is 1 + 1 + 1 + 1 + 1 == 5? A. true B. false C. There is no guarantee that 1 + 1 + 1 + 1 + 1 == 5 is true.

What is the index variable for the element at the first row and first column in array a? A. a[0][0] B. a[1][1] C. a[0][1] D. a[1][0]

What is the representation of the third element in an array called a? A. a[2] B. a(2) C. a[3] D. a(3)

When you create an array using the following statement, the element values are automatically initialized to 0. int[][] matrix = new int[5][5]; A. True B. False

What is y displayed in the following code? public class Test { public static void main(String[] args) { int x = 1; int y = x++ + x; System.out.println("y is " + y); } } A. y is 1. B. y is 2. C. y is 3. D. y is 4

What is y displayed in the following code? public class Test1 { public static void main(String[] args) { int x = 1; int y = x = x + 1; System.out.println("y is " + y); } } A. y is 0. B. y is 1 because x is assigned to y first. C. y is 2 because x + 1 is assigned to x and then x is assigned to y. D. The program has a compile error since x is redeclared in the statement int y = x = x + 1

What modifier should you use on the members of a class so that they are not accessible to another class in a different package, but are accessible to any subclasses in any package? A. public B. private C. protected D. Use the default modifier

What will be displayed when the following code is executed? int number = 6; while (number > 0) { number -= 3; System.out.print(number + " "); } A. 6 3 0 B. 6 3 C. 3 0 D. 3 0 -3 E. 0 -3

When invoking a method with an object argument, ___________ is passed. A. the contents of the object B. a copy of the object C. the reference of the object D. the object is copied, then the reference of the copied object

When you pass an array to a method, the method receives __________. A. a copy of the array B. a copy of the first element C. the reference of the array D. the length of the array

When you return an array from a method, the method returns __________. A. a copy of the array B. a copy of the first element C. the reference of the array D. the length of the array

Which of the following statements are true? A. The String class implements Comparable. B. The Date class implements Comparable. C. The Double class implements Comparable. D. The BigInteger class implements Comparable

A, B, C and D

Math.cos(Math.PI) returns _______. A. 0.0 B. 1.0 C. -1.0 D. 0.5

Suppose an ArrayList list contains {"red", "red", "green"}. What is the list after the following code? String element = "red"; for (int i = list.size() - 1; i >= 0; i--) if (list.get(i).equals(element)) list.remove(element); A. {"red", "red", "green"} B. {"red", "green"} C. {"green"} D. {}

Suppose x is a char variable with a value 'b'. What is the output of the statement System.out.println(++x)? A. a B. b C. c D. d

Suppose x is 1. What is x after x += 2? A. 0 B. 1 C. 2 D. 3 E. 4

Which of the following expression results in a value 1? A. 2 % 1 B. 15 % 4 C. 25 % 5 D. 37 % 6

You can assign _________ to a variable of Object[] type. A. new char[100] B. new int[100] C. new double[100] D. new String[100] E. new java.util.Date[100]

D and E

To declare a constant MAX_LENGTH as a member of the class, you write A. final static MAX_LENGTH = 99.98; B. final static float MAX_LENGTH = 99.98; C. static double MAX_LENGTH = 99.98; D. final double MAX_LENGTH = 99.98; E. final static double MAX_LENGTH = 99.98;

To obtain the current hour in UTC, use _________. A. System.currentTimeMillis() % 3600 B. System.currentTimeMillis() % 60 C. System.currentTimeMillis() / 1000 % 60 D. System.currentTimeMillis() / 1000 / 60 % 60 E. System.currentTimeMillis() / 1000 / 60 / 60 % 24

Use the selectionSort method presented in this section to answer this question. Assume list is {3.1, 3.1, 2.5, 6.4, 2.1}, what is the content of list after the first iteration of the outer loop in the method? A. 3.1, 3.1, 2.5, 6.4, 2.1 B. 2.5, 3.1, 3.1, 6.4, 2.1 C. 2.1, 2.5, 3.1, 3.1, 6.4 D. 3.1, 3.1, 2.5, 2.1, 6.4 E. 2.1, 3.1, 2.5, 6.4, 3.1

What balance after the following code is executed? int balance = 10; while (balance >= 1) { if (balance < 9) continue; balance = balance - 9; } A. -1 B. 0 C. 1 D. 2 E. The loop does not end

What exception type does the following program throw? public class Test { public static void main(String[] args) { Object o = null; System.out.println(o.toString()); } } A. ArithmeticException B. ArrayIndexOutOfBoundsException C. StringIndexOutOfBoundsException D. ClassCastException E. NullPointerException

What is the output for y? int y = 0; for (int i = 0; i < 10; ++i) { y += i; } System.out.println(y); A. 10 B. 11 C. 12 D. 13 E. 45

Math.pow(4, 1 / 2) returns ________

1.0 Note that 1 / 2 is 0

Suppose int i = 5, which of the following can be used as an index for array double[] t = new double[100]? A. i B. (int)(Math.random() * 100)) C. i + 10 D. i + 6.5 E. Math.random() * 100

A, B and C

Suppose you enter 34.3, the ENTER key, 57.8, the ENTER key, abc, the Enter key. Analyze the following code. 1 Scanner input = new Scanner(System.in); 2 double v1 = input.nextDouble(); 3 double v2 = input.nextDouble(); 4 String line = input.nextLine(); A. After line 2 is executed, v1 is 34.3. B. After line 3 is executed, v2 is 57.8. C. After line 4 is executed, line contains an empty string. D. After line 4 is executed, line is null. E. After line 4 is executed, line contains character "abc"

A, B and C

The extension name of a Java bytecode file is

.class

The extension name of a Java source code file is

.java

-25 % 5 is ____

25 % 1 is ____

What is the result of 45 / 4?

The "less than or equal to" comparison operator in Java is ________

____________ is the Java assignment operator

The equal comparison operator in Java is _______

(char)('a' + Math.random() * ('z' - 'a' + 1)) returns a random character __________. A. between 'a' and 'z' B. between 'a' and 'y' C. between 'b' and 'z' D. between 'b' and 'y'

An aggregation relationship is usually represented as __________ in ___________. A. a data field/the aggregating class B. a data field/the aggregated class C. a method/the aggregating class D. a method/the aggregated class

An instance of _________ describes programming errors, such as bad casting, accessing an out-of-bounds array, and numeric errors.. A. RuntimeException B. Exception C. Error D. Throwable E. NumberFormatException

Analyze the following code. // Program 1 public class Test { public static void main(String[] args) { Object a1 = new A(); Object a2 = new A(); System.out.println(((A)a1).equals((A)a2)); } } class A { int x; public boolean equals(A a) { return this.x == a.x; } } // Program 2 public class Test { public static void main(String[] args) { A a1 = new A(); A a2 = new A(); System.out.println(a1.equals(a2)); } } class A { int x; public boolean equals(A a) { return this.x == a.x; } } A. Program 1 displays true and Program 2 displays true B. Program 1 displays false and Program 2 displays true C. Program 1 displays true and Program 2 displays false D. Program 1 displays false and Program 2 displays false

Analyze the following code. class Test { public static void main(String[] args) { String s; System.out.println("s is " + s); } } A. The program has a compile error because s is not initialized, but it is referenced in the println statement. B. The program has a runtime error because s is not initialized, but it is referenced in the println statement. C. The program has a runtime error because s is null in the println statement. D. The program compiles and runs fine

An int variable can hold __________. A. 'x' B. 120 C. 120.0 D. "x" E. "120"

A and B

The client can use a method without knowing how it is implemented. The details of the implementation are encapsulated in the method and hidden from the client who invokes the method. This is known as __________. A. information hiding B. encapsulation C. method hiding D. simplifying method

A and B

The java.util.Date class is introduced in this section. Analyze the following code and choose the best answer: Which of the following code in A or B, or both creates an object of the Date class: A: public class Test { public Test() { new java.util.Date(); } } B: public class Test { public Test() { java.util.Date date = new java.util.Date(); } } A. A. B. B. C. Neither

A and B

Which of the following are correct ways to declare variables? A. int length; int width; B. int length, width; C. int length; width; D. int length, int width;

A and B

Which of the following assignment statements is correct? A. char c = 'd'; B. char c = 100; C. char c = "d"; D. char c = "100";

A and B

Which of the following statements are correct? A. new java.math.BigInteger("343"); B. new java.math.BigDecimal("343.445"); C. new java.math.BigInteger(343); D. new java.math.BigDecimal(343.445);

A and B

To assign a value 1 to variable x, you write

x = 1;

____________ seeks to analyze the data flow and to identify the system?s input and output. When you do analysis, it helps to identify what the output is first, and then figure out what input data you need in order to produce the output

Analysis

The following program displays __________. public class Test { public static void main(String[] args) { String s = "Java"; StringBuilder buffer = new StringBuilder(s); change(buffer); System.out.println(buffer); } private static void change(StringBuilder buffer) { buffer.append(" and HTML"); } } A. Java B. Java and HTML C. and HTML D. nothing is displayed

Does the method call in the following method cause compile errors? public static void main(String[] args) { Math.pow(2, 4); } A. Yes B. No

Does the return statement in the following method cause compile errors? public static void main(String[] args) { int max = 0; if (max != 0) System.out.println(max); else return; } A. Yes B. No

Given the following classes and their objects: class C1 {}; class C2 extends C1 {}; class C3 extends C1 {}; C2 c2 = new C2(); C3 c3 = new C3(); Analyze the following statement: c2 = (C2)((C1)c3); A. c3 is cast into c2 successfully. B. You will get a runtime error because you cannot cast objects from sibling classes. C. You will get a runtime error because the Java runtime system cannot perform multiple casting in nested form. D. The statement is correct

Given |x - 2| >= 4, which of the following is true? A. x - 2 >= 4 && x - 2 <= -4 B. x - 2 >= 4 || x - 2 <= -4 C. x - 2 >= 4 && x - 2 < -4 D. x - 2 >= 4 || x - 2 < -4

How many elements are in array double[] list = new double[5]? A. 4 B. 5 C. 6 D. 0

If you declare an array double[] list = {3.4, 2.0, 3.5, 5.5}, list[1] is ________. A. 3.4 B. 2.0 C. 3.5 D. 5.5 E. undefined

Inheritance means ______________. A. that data fields should be declared private B. that a class can extend another class C. that a variable of supertype can refer to a subtype object D. that a class can contain another class

Invoking _________ returns the first element in an ArrayList x. A. x.first() B. x.get(0) C. x.get(1) D. x.get()

Suppose an ArrayList list contains {"red", "green", "red", "green"}. What is the list after the following code? list.remove("red"); A. {"red", "green", "red", "green"} B. {"green", "red", "green"} C. {"green", "green"} D. {"red", "green", "green"}

Suppose an ArrayList list contains {"red", "red", "green"}. What is the list after the following code? String element = "red"; for (int i = 0; i < list.size(); i++) if (list.get(i).equals(element)) list.remove(element); A. {"red", "red", "green"} B. {"red", "green"} C. {"green"} D. {}

Suppose i is an int type variable. Which of the following statements display the character whose Unicode is stored in variable i? A. System.out.println(i); B. System.out.println((char)i); C. System.out.println((int)i); D. System.out.println(i + " ");

Suppose income is 4001, what is the output of the following code? if (income > 3000) { System.out.println("Income is greater than 3000"); } else if (income > 4000) { System.out.println("Income is greater than 4000"); } A. no output B. Income is greater than 3000 C. Income is greater than 3000 followed by Income is greater than 4000 D. Income is greater than 4000 E. Income is greater than 4000 followed by Income is greater than 3000

Suppose x = 1, y = -1, and z = 1. What is the output of the following statement? (Please indent the statement correctly first.) if (x > 0) if (y > 0) System.out.println("x > 0 and y > 0"); else if (z > 0) System.out.println("x < 0 and z > 0"); A. x > 0 and y > 0; B. x < 0 and z > 0; C. x < 0 and z < 0; D. no output

Suppose x=10 and y=10. What is x after evaluating the expression (y > 10) && (x++ > 10). A. 9 B. 10 C. 11

Suppose x=10 and y=10. What is x after evaluating the expression (y > 10) && (x-- > 10)? A. 9 B. 10 C. 11

Suppose x=10 and y=10. What is x after evaluating the expression (y >= 10) || (x++ > 10). A. 9 B. 10 C. 11

Suppose x=10 and y=10. What is x after evaluating the expression (y >= 10) || (x-- > 10). A. 9 B. 10 C. 11

Suppose you enter 34.3 57.8 789, then press the ENTER key. Analyze the following code. Scanner input = new Scanner(System.in); int v1 = input.nextInt(); int v2 = input.nextInt(); String line = input.nextLine(); A. After the last statement is executed, v1 is 34. B. The program has a runtime error because 34.3 is not an integer. C. After the last statement is executed, line contains characters '7', '8', '9', '\n'. D. After the last statement is executed, line contains characters '7', '8', '9'

Suppose you write the code to display "Cannot get a driver's license" if age is less than 16 and "Can get a driver's license" if age is greater than or equal to 16. Which of the following code is the best? I: if (age < 16) System.out.println("Cannot get a driver's license"); if (age >= 16) System.out.println("Can get a driver's license"); II: if (age < 16) System.out.println("Cannot get a driver's license"); else System.out.println("Can get a driver's license"); III: if (age < 16) System.out.println("Cannot get a driver's license"); else if (age >= 16) System.out.println("Can get a driver's license"); IV: if (age < 16) System.out.println("Cannot get a driver's license"); else if (age > 16) System.out.println("Can get a driver's license"); else if (age == 16) System.out.println("Can get a driver's license"); A. I B. II C. III D. IV

The JVM stores the array in an area of memory, called _______, which is used for dynamic memory allocation where blocks of memory are allocated and freed in an arbitrary order. A. stack B. heap C. memory block D. dynamic memory

The __________ method parses a string s to an int value. A. integer.parseInt(s); B. Integer.parseInt(s); C. integer.parseInteger(s); D. Integer.parseInteger(s);

The default value for data field of a boolean type, numeric type, object type is ___________, respectively. A. true, 1, Null B. false, 0, null C. true, 0, null D. true, 1, null E. false, 1, null

The equals method is defined in the Object class. Which of the following is correct to override it in the String class? A. public boolean equals(String other) B. public boolean equals(Object other) C. public static boolean equals(String other) D. public static boolean equals(Object other)

The expression (int)(76.0252175 * 100) / 100 evaluates to _________. A. 76.02 B. 76 C. 76.0252175 D. 76.03

Suppose ArrayList x contains two strings [Beijing, Singapore]. Which of the following method will cause runtime errors? A. x.get(1) B. x.set(2, "New York"); C. x.get(2) D. x.remove(2) E. x.size()

B, C and D

To obtain the distance between the points (40, 50) and (5.5, 4.4), use _________. A. distance(40, 50, 5.5, 4.4) B. new Point2D(40, 50).distance(5.5, 4.4) C. new Point2D(40, 50).distance(new Point2D(5.5, 4.4)) D. new Point2D(5.5, 4.4).distance(40, 50) E. new Point2D(5.5, 4.4).distance(new Point2D(40, 50))

B, C, D and E

Which of the following statements are true? A. A Scene is a Node. B. A Shape is a Node. C. A Stage is a Node. D. A Control is a Node. E. A Pane is a Node.

B, D and E

Which of the following statements correctly creates a Color object? A. new Color(3, 5, 5, 1); B. new Color(0.3, 0.5, 0.5, 0.1); C. new Color(0.3, 0.5, 0.5); D. Color.color(0.3, 0.5, 0.5); E. Color.color(0.3, 0.5, 0.5, 0.1);

B, D and E

To add a value 1 to variable x, you write: A. 1 + x = x; B. x += 1; C. x := 1; D. x = x + 1; E. x = 1 + x;

B, D, and E

Which of the following expressions will yield 0.5? A. 1 / 2 B. 1.0 / 2 C. (double) (1 / 2) D. (double) 1 / 2 E. 1 / 2.0

B, D, and E

A block is enclosed inside __________

Braces

(int)(Math.random() * (65535 + 1)) returns a random number __________. A. between 1 and 65536 B. between 1 and 65535 C. between 0 and 65535 D. between 0 and 65536

A class design requires that a particular member variable must be accessible by any subclasses of this class, but otherwise not by classes which are not members of the same package. What should be done to achieve this? A. The variable should be marked public. B. The variable should be marked private. C. The variable should be marked protected. D. The variable should have no special access modifier. E. The variable should be marked private and an accessor method provided

A method that is associated with an individual object is called __________. A. a static method B. a class method C. an instance method D. an object method

Analyze the following code and choose the best answer: public class Foo { private int x; public static void main(String[] args) { Foo foo = new Foo(); System.out.println(foo.x); } } A. Since x is private, it cannot be accessed from an object foo. B. Since x is defined in the class Foo, it can be accessed by any method inside the class without using an object. You can write the code to access x without creating an object such as foo in this code. C. Since x is an instance variable, it cannot be directly used inside a main method. However, it can be accessed through an object such as foo in this code. D. You cannot create a self-referenced object; that is, foo is created inside the class Foo

Analyze the following code. // Program 1: public class Test { public static void main(String[] args) { Object a1 = new A(); Object a2 = new A(); System.out.println(a1.equals(a2)); } } class A { int x; public boolean equals(Object a) { return this.x == ((A)a).x; } } // Program 2: public class Test { public static void main(String[] args) { Object a1 = new A(); Object a2 = new A(); System.out.println(a1.equals(a2)); } } class A { int x; public boolean equals(A a) { return this.x == a.x; } } A. Program 1 displays true and Program 2 displays true B. Program 1 displays false and Program 2 displays true C. Program 1 displays true and Program 2 displays false D. Program 1 displays false and Program 2 displays false

Analyze the following code: public class Test { public static void main (String args[]) { int i = 0; for (i = 0; i < 10; i++); System.out.println(i + 4); } } A. The program has a compile error because of the semicolon (;) on the for loop line. B. The program compiles despite the semicolon (;) on the for loop line, and displays 4. C. The program compiles despite the semicolon (;) on the for loop line, and displays 14. D. The for loop in this program is same as for (i = 0; i < 10; i++) { }; System.out.println(i + 4);

C and D

If a key is not in the list, the binarySearch method returns _________. A. insertion point B. insertion point - 1 C. -(insertion point + 1) D. -insertion point

In the following code, what is the output for list1? public class Test { public static void main(String[] args) { int[] list1 = {1, 2, 3}; int[] list2 = {1, 2, 3}; list2 = list1; list1[0] = 0; list1[1] = 1; list2[2] = 2; for (int i = 0; i < list1.length; i++) System.out.print(list1[i] + " "); } } A. 1 2 3 B. 1 1 1 C. 0 1 2 D. 0 1 3

In the following code, what is the output for list2? public class Test { public static void main(String[] args) { int[] list1 = {1, 2, 3}; int[] list2 = {1, 2, 3}; list2 = list1; list1[0] = 0; list1[1] = 1; list2[2] = 2; for (int i = 0; i < list2.length; i++) System.out.print(list2[i] + " "); } } A. 1 2 3 B. 1 1 1 C. 0 1 2 D. 0 1 3

Polymorphism means ______________. A. that data fields should be declared private B. that a class can extend another class C. that a variable of supertype can refer to a subtype object D. that a class can contain another class

Show the output of the following code: String[] array = {"red", "green", "blue"}; ArrayList<String> list = new ArrayList<>(Arrays.asList(array)); list.add(0, "red"); System.out.println(list); A. ["red", "green", "blue", "red"] B. ["red", "green", "blue"] C. ["red", "red", "green", "blue"] D. ["red", "green", "red", "blue"]

Suppose ArrayList x contains two strings [Beijing, Singapore]. Which of the following methods will cause the list to become [Beijing, Chicago, Singapore]? A. x.add("Chicago") B. x.add(0, "Chicago") C. x.add(1, "Chicago") D. x.add(2, "Chicago")

Suppose TestSimpleCircle and SimpleCircle in Listing 9.1 are in two separate files named TestSimpleCircle.java and SimpleCircle.java, respectively. What is the outcome of compiling TestsimpleCircle.java and then SimpleCircle.java? A. Only TestSimpleCircle.java compiles. B. Only SimpleCircle.java compiles. C. Both compile fine. D. Neither compiles successfully

Suppose an ArrayList list contains {"red", "red", "green"}. What is the list after the following code? String element = "red"; for (int i = 0; i < list.size(); i++) if (list.get(i).equals(element)) { list.remove(element); i--; } A. {"red", "red", "green"} B. {"red", "green"} C. {"green"} D. {}

Suppose isPrime is a boolean variable, which of the following is the correct and best statement for testing if isPrime is true. A. if (isPrime = true) B. if (isPrime == true) C. if (isPrime) D. if (!isPrime = false) E. if (!isPrime == false)

Suppose s is a string with the value "java". What will be assigned to x if you execute the following code? char x = s.charAt(4); A. 'a' B. 'v' C. Nothing will be assigned to x, because the execution causes the runtime error StringIndexOutofBoundsException.

Suppose the xMethod() is invoked in the following constructor in a class, xMethod() is _________ in the class. public MyClass() { xMethod(); } A. a static method B. an instance method C. a static method or an instance method

Suppose you wish to provide an accessor method for a boolean property finished, what signature of the method should be? A. public void getFinished() B. public boolean getFinished() C. public boolean isFinished() D. public void isFinished()

The JDK command to compile a class in the file Test.java is: A. java Test B. java Test.java C. javac Test.java D. javac Test E. JAVAC Test.java

The __________ method immediately terminates the program. A. System.terminate(0); B. System.halt(0); C. System.exit(0); D. System.quit(0); E. System.stop(0);

The __________ method sorts the array scores of the double[] type. A. java.util.Arrays(scores) B. java.util.Arrays.sorts(scores) C. java.util.Arrays.sort(scores) D. Njava.util.Arrays.sortArray(scores)

The expression "Java " + 1 + 2 + 3 evaluates to ________. A. Java123 B. Java6 C. Java 123 D. java 123 E. Illegal expression

The following code displays ___________. double temperature = 50; if (temperature >= 100) System.out.println("too hot"); else if (temperature <= 40) System.out.println("too cold"); else System.out.println("just right"); A. too hot B. too cold C. just right D. too hot too cold just right

Which of the following is the best for generating random integer 0 or 1? A. (int)Math.random() B. (int)Math.random() + 1 C. (int)(Math.random() + 0.5) D. (int)(Math.random() + 0.2) E. (int)(Math.random() + 0.8)

Which of the following is the correct statement to return JAVA? A. toUpperCase("Java") B. "Java".toUpperCase("Java") C. "Java".toUpperCase() D. String.toUpperCase("Java")

Which of the following statements is false? A. If you compile an interface without errors, a .class file is created for the interface. B. If you compile a class without errors but with warnings, a .class file is created. C. If you compile a class with errors, a .class file is created for the class. D. If you compile an interface without errors, but with warnings, a .class file is created for the interface

Which of the statements regarding the super keyword is incorrect? A. You can use super to invoke a super class constructor. B. You can use super to invoke a super class method. C. You can use super.super.p to invoke a method in superclass's parent class. D. You cannot invoke a method in superclass's parent class

You can create an ArrayList using _________. A. new ArrayList[] B. new ArrayList[100] C. new ArrayList<>() D. ArrayList()

________ is not an object-oriented programming language A) Java B) C++ C) C D) C# E) Python

____________ is an operating system A) Java B) C++ C) Windows D) Visual Basic E) Ada

What is Math.ceil(3.6)? A. 3.0 B. 3 C. 4.0 D. 5.0

C Note ceil returns double value

What is Math.rint(3.6)? A. 3.0 B. 3 C. 4.0 D. 5.0

C Note rint returns a double value

What is Math.round(3.6)? A. 3.0 B. 3 C. 4 D. 4.0

C Note round returns an int value

Note that the Unicode for character A is 65. The expression "A" + 1 evaluates to ________. A. 66 B. B C. A1 D. Illegal expression

C When a sting adds with a number, the number is converted to a string

Analyze the following code: public class Test { public static void main(String[] args) { Object a1 = new A(); Object a2 = new Object(); System.out.println(a1); System.out.println(a2); } } class A { int x; @Override public String toString() { return "A's x is " + x; } } A. The program cannot be compiled, because System.out.println(a1) is wrong and it should be replaced by System.out.println(a1.toString()); B. When executing System.out.println(a1), the toString() method in the Object class is invoked. C. When executing System.out.println(a2), the toString() method in the Object class is invoked. D. When executing System.out.println(a1), the toString() method in the A class is invoked

C and D

Suppose s1 and s2 are two strings. Which of the following statements or expressions are incorrect? A. String s = new String("new string"); B. String s3 = s1 + s2 C. s1 >= s2 D. int i = s1.length E. s1.charAt(0) = '5'

C, D and E

Which of the following are incorrect? A. An abstract class contains constructors. B. The constructors in an abstract class should be protected. C. The constructors in an abstract class are private. D. You may declare a final abstract class. E. An interface may contain constructors

C, D and E

Which of the following is incorrect? A. int[] a = new int[2]; B. int a[] = new int[2]; C. int[] a = new int(2); D. int a = new int[2]; E. int a() = new int[2];

C, D, and E

____________________ returns true. A. "peter".compareToIgnoreCase("Peter") B. "peter".compareToIgnoreCase("peter") C. "peter".equalsIgnoreCase("Peter") D. "peter".equalsIgnoreCase("peter") E. "peter".equals("peter")

C, D, and E

To create an instance of BigDecimal for 454.45, use A. BigInteger(454.45); B. new BigInteger(454.45); C. BigInteger("454.45"); D. new BigDecimal("454.45");

To create an instance of BigInteger for 454, use A. BigInteger(454); B. new BigInteger(454); C. BigInteger("454"); D. new BigInteger("454");

To declare a constant MAX_LENGTH inside a method with value 99.98, you write: A. final MAX_LENGTH = 99.98; B. final float MAX_LENGTH = 99.98; C. double MAX_LENGTH = 99.98; D. final double MAX_LENGTH = 99.98;

To obtain the current minute, use _________. A. System.currentTimeMillis() % 3600 B. System.currentTimeMillis() % 60 C. System.currentTimeMillis() / 1000 % 60 D. System.currentTimeMillis() / 1000 / 60 % 60 E. System.currentTimeMillis() / 1000 / 60 / 60 % 24

To place two nodes node1 and node2 in a HBox p, use ___________. A. p.add(node1, node2); B. p.addAll(node1, node2); C. p.getChildren().add(node1, node2); D. p.getChildren().addAll(node1, node2);

To remove two nodes node1 and node2 from a pane, use ______. A. pane.remove(node1, node2); B. pane.removeAll(node1, node2); C. pane.getChildren().remove(node1, node2); D. pane.getChildren().removeAll(node1, node2);

Variables that are shared by every instances of a class are __________. A. public variables B. private variables C. instance variables D. class variables

What exception type does the following program throw? public class Test { public static void main(String[] args) { Object o = new Object(); String d = (String)o; } } A. ArithmeticException B. ArrayIndexOutOfBoundsException C. StringIndexOutOfBoundsException D. ClassCastException E. No exception

What exception type does the following program throw? public class Test { public static void main(String[] args) { Object o = null; System.out.println(o); } } A. ArithmeticException B. ArrayIndexOutOfBoundsException C. StringIndexOutOfBoundsException D. No exception E. NullPointerException

What is displayed by the following code? System.out.print("Hi, ABC, good".matches("ABC ") + " "); System.out.println("Hi, ABC, good".matches(".*ABC.*")); A. false false B. true false C. true true D. false true

What is displayed on the console when running the following program? public class Test { public static void main(String[] args) { try { System.out.println("Welcome to Java"); int i = 0; int y = 2/i; System.out.println("Welcome to Java"); } finally { System.out.println("End of the block"); } System.out.println("End of the block"); } } A. The program displays Welcome to Java three times followed by End of the block. B. The program displays Welcome to Java two times followed by End of the block. C. The program displays Welcome to Java two times followed by End of the block two times. D. The program displays Welcome to Java and End of the block, and then terminates because of an unhandled exception

What is i after the following for loop? int y = 0; for (int i = 0; i < 10; ++i) { y += i; } A. 9 B. 10 C. 11 D. undefined

What is i printed? public class Test { public static void main(String[] args) { int j = 0; int i = ++j + j * 5; System.out.println("What is i? " + i); } } A. 0 B. 1 C. 5 D. 6

What is k after the following block executes? { int k = 2; nPrint("A message", k); } System.out.println(k); A. 0 B. 1 C. 2 D. k is not defined outside the block. So, the program has a compile error

What is output of the following code: public class Test { public static void main(String[] args) { int list[] = {1, 2, 3, 4, 5, 6}; for (int i = 1; i < list.length; i++) list[i] = list[i - 1]; for (int i = 0; i < list.length; i++) System.out.print(list[i] + " "); } } A. 1 2 3 4 5 6 B. 2 3 4 5 6 6 C. 2 3 4 5 6 1 D. 1 1 1 1 1 1

What is the output after the following loop terminates? int number = 25; int i; boolean isPrime = true; for (i = 2; i < number && isPrime; i++) { if (number % i == 0) { isPrime = false; } } System.out.println("i is " + i + " isPrime is " + isPrime); A. i is 5 isPrime is true B. i is 5 isPrime is false C. i is 6 isPrime is true D. i is 6 isPrime is false

What is the output for the first statement in the main method? public class Foo { static int i = 0; static int j = 0; public static void main(String[] args) { int i = 2; int k = 3; { int j = 3; System.out.println("i + j is " + i + j); } k = i + j; System.out.println("k is " + k); System.out.println("j is " + j); } } A. i + j is 5 B. i + j is 6 C. i + j is 22 D. i + j is 23

What is the output of the following code: double x = 5.5; int y = (int)x; System.out.println("x is " + x + " and y is " + y); A. x is 5 and y is 6 B. x is 6.0 and y is 6.0 C. x is 6 and y is 6 D. x is 5.5 and y is 5 E. x is 5.5 and y is 5.0

What is the output of the following code? int[] myList = {1, 2, 3, 4, 5, 6}; for (int i = myList.length - 2; i >= 0; i--) { myList[i + 1] = myList[i]; } for (int e: myList) System.out.print(e + " "); A. 1 2 3 4 5 6 B. 6 1 2 3 4 5 C. 6 2 3 4 5 1 D. 1 1 2 3 4 5 E. 2 3 4 5 6 1

What is the output of the following code? String s = "University"; s.replace("i", "ABC"); System.out.println(s); A. UnABCversity B. UnABCversABCty C. UniversABCty D. University

What is the output of the following code? public class Test { public static void main(String[] args) { int[][] matrix = {{1, 2, 3, 4}, {4, 5, 6, 7}, {8, 9, 10, 11}, {12, 13, 14, 15}}; for (int i = 0; i < 4; i++) System.out.print(matrix[i][1] + " "); } } A. 1 2 3 4 B. 4 5 6 7 C. 1 3 8 12 D. 2 5 9 13 E. 3 6 10 14

What is the output of the following code? public class Test { public static void main(String[] args) { int[][][] data = {{{1, 2}, {3, 4}}, {{5, 6}, {7, 8}}}; System.out.print(data[1][0][0]); } } A. 1 B. 2 C. 4 D. 5 E. 6

What is the output of the following program? public class Test { public static void main(String[] args) { int[][] values = {{3, 4, 5, 1 }, {33, 6, 1, 2}}; for (int row = 0; row < values.length; row++) { java.util.Arrays.sort(values[row]); for (int column = 0; column < values[row].length; column++) System.out.print(values[row][column] + " "); System.out.println(); } } } A. The program prints two rows 3 4 5 1 followed by 33 6 1 2 B. The program prints on row 3 4 5 1 33 6 1 2 C. The program prints two rows 3 4 5 1 followed by 2 1 6 33 D. The program prints two rows 1 3 4 5 followed by 1 2 6 33 E. The program prints one row 1 3 4 5 1 2 6 33

What is the output of the following program? public class Test { public static void main(String[] args) { int[][] values = {{3, 4, 5, 1}, {33, 6, 1, 2}}; for (int row = 0; row < values.length; row++) { System.out.print(m(values[row]) + " "); } } public static int m(int[] list) { int v = list[0]; for (int i = 1; i < list.length; i++) if (v < list[i]) v = list[i]; return v; } } A. 3 33 B. 1 1 C. 5 6 D. 5 33 E. 33 5

What is x after the following statements? int x = 2; int y = 1; x *= y + 1; A. x is 1. B. x is 2. C. x is 3. D. x is 4.

What modifier should you use on a class so that a class in the same package can access it but a class in a different package cannot access it? A. public B. private C. protected D. Use the default modifier

Which of the following is a correct interface? A. interface A { void print() { }; } B. abstract interface A { print(); } C. abstract interface A { abstract void print() { };} D. interface A { void print();}

Which of the following is the correct expression of character 4? A. 4 B. "4" C. '\0004' D. '4'

Which of the following statements are correct? A. char[][] charArray = {'a', 'b'}; B. char[2][2] charArray = {{'a', 'b'}, {'c', 'd'}}; C. char[2][] charArray = {{'a', 'b'}, {'c', 'd'}}; D. char[][] charArray = {{'a', 'b'}, {'c', 'd'}};

Which of the following statements is false? A. A public class can be accessed by a class from a different package. B. A private method cannot be accessed by a class in a different package. C. A protected method can be accessed by a subclass in a different package. D. A method with no visibility modifier can be accessed by a class in a different package

Which of the following statements is false? A. You can always pass an instance of a subclass to a parameter of its superclass type. This feature is known as polymorphism. B. The compiler finds a matching method according to parameter type, number of parameters, and order of the parameters at compile time. C. A method may be implemented in several subclasses. The Java Virtual Machine dynamically binds the implementation of the method at runtime. D. Dynamic binding can apply to static methods. E. Dynamic binding can apply to instance methods

Which of the following statements will convert a string s into a double value d? A. d = Double.parseDouble(s); B. d = (new Double(s)).doubleValue(); C. d = Double.valueOf(s).doubleValue(); D. All of the aboveD

You can declare two variables with the same name in __________. A. a method one as a formal parameter and the other as a local variable B. a block C. two nested blocks in a method (two nested blocks means one being inside the other) D. different methods in a class

You should fill in the blank in the following code with ______________. public class Test { public static void main(String[] args) { System.out.print("The grade is " + getGrade(78.5)); System.out.print("\nThe grade is " + getGrade(59.5)); } public static _________ getGrade(double score) { if (score >= 90.0) return 'A'; else if (score >= 80.0) return 'B'; else if (score >= 70.0) return 'C'; else if (score >= 60.0) return 'D'; else return 'F'; } } A. int B. double C. boolean D. char E. void

______ is not a reference type. A. A class type B. An interface type C. An array type D. A primitive type

To add number to sum, you write (Note: Java is case-sensitive) A. number += sum; B. number = sum + number; C. sum = Number + sum; D. sum += number; E. sum = sum + number;

D and E

Which of the following assignment statements is illegal? A. float f = -34; B. int t = 23; C. short s = 10; D. int t = (int)false; E. int t = 4.5;

D and E

Which of the following declarations are correct? A. public static void print(String... strings, double... numbers) B. public static void print(double... numbers, String name) C. public static double... print(double d1, double d2) D. public static void print(double... numbers) E. public static void print(int n, double... numbers)

D and E

Analyze the following code fragments that assign a boolean value to the variable even. Code 1: if (number % 2 == 0) even = true; else even = false; Code 2: even = (number % 2 == 0) ? true: false; Code 3: even = number % 2 == 0; A. Code 2 has a compile error, because you cannot have true and false literals in the conditional expression. B. Code 3 has a compile error, because you attempt to assign number to even. C. All three are correct, but Code 1 is preferred. D. All three are correct, but Code 2 is preferred. E. All three are correct, but Code 3 is preferred.

____________ is a device to connect a computer to a local area network (LAN)

Network Interface Card (NIC)

_____________ is a program that runs on a computer to manage and control a computer's activities

Operating system

____________ are instructions to the computer

Software and Programs

Suppose you define a Java class as follows: public class Test { } In order to compile this program, the source code should be stored in a file named ____________

Test.java

Java was developed by ____________

Sun Microsystems

Are the following four statements equivalent? number += 1; number = number + 1; number++; ++number;

Yes

To improve readability and maintainability, you should declare _________ instead of using literal values such as 3.14159

constants

To declare an int variable number with initial value 2, you write

int number = 2;

Computer can execute the code in ____________

machine language

When assigning a literal to a variable of the byte type, if the literal is too large to be stored as a byte value, it ____________

receives a compile error

If you attempt to add an int, a byte, a long, and a double, the result will be a __________ value

double

The speed of the CPU may be measured in __________

megahertz and gigahertz

Math.pow(2, 3) returns _______

8.0

What is the output of System.out.println('z' - 'a')? A. 25 B. 26 C. a D. z

What is the output from System.out.println((int)Math.random( ) * 4)? A. 0 B. 1 C. 2 D. 3 E. 4

-24 % -5 is ____

-4

-24 % 5 is ____

-4

Math.pow(4, 1.0 / 2) returns _____

2.0

what is the value of (double)(5/2)?

2.0

What is the value of (double)5/2?

2.5

The expression 4 + 20 / (3 - 1) * 2 is evaluated to

24 % 5 is ____

Analyze the following code. public class Test { public static void main(String[] args) { System.out.println(m(2)); } public static int m(int num) { return num; } public static void m(int num) { System.out.println(num); } } A. The program has a compile error because the two methods m have the same signature. B. The program has a compile error because the second m method is defined, but not invoked in the main method. C. The program runs and prints 2 once. D. The program runs and prints 2 twice

Analyze the following code: if (x < 100) && (x > 10) System.out.println("x is between 10 and 100"); A. The statement has compile errors because (x<100) & (x > 10) must be enclosed inside parentheses. B. The statement has compile errors because (x<100) & (x > 10) must be enclosed inside parentheses and the println(?) statement must be put inside a block. C. The statement compiles fine. D. The statement compiles fine, but has a runtime error

Analyze the following code: import javafx.application.Application; import javafx.scene.Scene; import javafx.stage.Stage; import javafx.scene.layout.HBox; import javafx.scene.shape.Circle; public class Test extends Application { @Override // Override the start method in the Application class public void start(Stage primaryStage) { HBox pane = new HBox(5); Circle circle = new Circle(50, 200, 200); pane.getChildren().addAll(circle); circle.setCenterX(100); circle.setCenterY(100); circle.setRadius(50); pane.getChildren().addAll(circle); // Create a scene and place it in the stage Scene scene = new Scene(pane); primaryStage.setTitle("Test"); // Set the stage title primaryStage.setScene(scene); // Place the scene in the stage primaryStage.show(); // Display the stage } /** * The main method is only needed for the IDE with limited * JavaFX support. Not needed for running from the command line. */ public static void main(String[] args) { launch(args); } } A. The program has a compile error since the circle is added to a pane twice. B. The program has a runtime error since the circle is added to a pane twice. C. The program runs fine and displays one circle. D. The program runs fine and displays two circles.

Analyze the following code: public class Test { public static void main(String args[]) { NClass nc = new NClass(); nc.t = nc.t++; } } class NClass { int t; private NClass() { } } A. The program has a compile error because the NClass class has a private constructor. B. The program does not compile because the parameter list of the main method is wrong. C. The program compiles, but has a runtime error because t has no initial value. D. The program compiles and runs fine

Analyze the following code: public class Test { public static void main(String[] args) throws MyException { System.out.println("Welcome to Java"); } } class MyException extends Error { } A. You should not declare a class that extends Error, because Error raises a fatal error that terminates the program. B. You cannot declare an exception in the main method. C. You declared an exception in the main method, but you did not throw it. D. The program has a compile error

Analyze the following code: public class Test { public static void main(String[] args) { System.out.println(xMethod(5, 500L)); } public static int xMethod(int n, long l) { System.out.println("int, long"); return n; } public static long xMethod(long n, long l) { System.out.println("long, long"); return n; } } A. The program displays int, long followed by 5. B. The program displays long, long followed by 5. C. The program runs fine but displays things other than 5. D. The program does not compile because the compiler cannot distinguish which xmethod to invoke

Analyze the following code: public class Test { public static void main(String[] args) { double radius; final double PI= 3.15169; double area = radius * radius * PI; System.out.println("Area is " + area); } } A. The program has compile errors because the variable radius is not initialized. B. The program has a compile error because a constant PI is defined inside a method. C. The program has no compile errors but will get a runtime error because radius is not initialized. D. The program compiles and runs fine.

Analyze the following code: public class Test { public static void main(String[] args) { int[] oldList = {1, 2, 3, 4, 5}; reverse(oldList); for (int i = 0; i < oldList.length; i++) System.out.print(oldList[i] + " "); } public static void reverse(int[] list) { int[] newList = new int[list.length]; for (int i = 0; i < list.length; i++) newList[i] = list[list.length - 1 - i]; list = newList; } } A. The program displays 1 2 3 4 5. B. The program displays 1 2 3 4 5 and then raises an ArrayIndexOutOfBoundsException. C. The program displays 5 4 3 2 1. D. The program displays 5 4 3 2 1 and then raises an ArrayIndexOutOfBoundsException

Analyze the following code: public class Test { public static void main(String[] args) { int[] x = {1, 2, 3, 4}; int[] y = x; x = new int[2]; for (int i = 0; i < y.length; i++) System.out.print(y[i] + " "); } } A. The program displays 1 2 3 4 B. The program displays 0 0 C. The program displays 0 0 3 4 D. The program displays 0 0 0 0

Analyze the following program. public class Test { public static void main(String[] args) { try { String s = "5.6"; Integer.parseInt(s); // Cause a NumberFormatException int i = 0; int y = 2 / i; System.out.println("Welcome to Java"); } catch (Exception ex) { System.out.println(ex); } } } A. An exception is raised due to Integer.parseInt(s); B. An exception is raised due to 2 / i; C. The program has a compile error. D. The program compiles and runs without exceptions

Assume Calendar calendar = new GregorianCalendar(). __________ returns the month of the year. A. calendar.get(Calendar.MONTH) B. calendar.get(Calendar.MONTH_OF_YEAR) C. calendar.get(Calendar.WEEK_OF_MONTH) D. calendar.get(Calendar.WEEK_OF_YEAR)

Assume Cylinder is a subtype of Circle. Analyze the following code: Circle c = new Circle (5); Cylinder c = cy; A. The code has a compile error. B. The code has a runtime error. C. The code is fine

Assume double[][][] x = new double[4][5][6], what are x.length, x[2].length, and x[0][0].length? A. 4, 5, and 6 B. 6, 5, and 4 C. 5, 5, and 5 D. 4, 5, and 4

BigInteger and BigDecimal are immutable A. true B. false

What is the output of the following code: public class Test { public static void main(String[] args) { Object o1 = new Object(); Object o2 = new Object(); System.out.print((o1 == o2) + " " + (o1.equals(o2))); } } A. false false B. true true C. false true D. true false

Do the following two programs produce the same result? Program I: public class Test { public static void main(String[] args) { int[] list = {1, 2, 3, 4, 5}; reverse(list); for (int i = 0; i < list.length; i++) System.out.print(list[i] + " "); } public static void reverse(int[] list) { int[] newList = new int[list.length]; for (int i = 0; i < list.length; i++) newList[i] = list[list.length - 1 - i]; list = newList; } } Program II: public class Test { public static void main(String[] args) { int[] oldList = {1, 2, 3, 4, 5}; reverse(oldList); for (int i = 0; i < oldList.length; i++) System.out.print(oldList[i] + " "); } public static void reverse(int[] list) { int[] newList = new int[list.length]; for (int i = 0; i < list.length; i++) newList[i] = list[list.length - 1 - i]; list = newList; } } A. Yes B. No

Do the following two statements in (I) and (II) result in the same value in sum? (I): for (int i = 0; i < 10; ++i) { sum += i; } (II): for (int i = 0; i < 10; i++) { sum += i; } A. Yes B. No

Encapsulation means ______________. A. that data fields should be declared private B. that a class can extend another class C. that a variable of supertype can refer to a subtype object D. that a class can contain another class

How many times is the println statement executed? for (int i = 0; i < 10; i++) for (int j = 0; j < 10; j++) System.out.println(i * j); A. 100 B. 20 C. 10 D. 45

In JDK 1.5, you may directly assign a primitive data type value to a wrapper object. This is called ______________. A. auto boxing B. auto unboxing C. auto conversion D. auto casting

Is the following loop correct? for ( ; ; ); A. Yes B. No

Note that the Unicode for character A is 65. The expression 'A' + 1 evaluates to ________. A. 66 B. B C. A1 D. Illegal expression

Suppose s1 and s2 are two strings. What is the result of the following code? s1.equals(s2) == s2.equals(s1) A. true B. false

Suppose the xMethod() is invoked from a main method in a class as follows, xMethod() is _________ in the class. public static void main(String[] args) { xMethod(); } A. a static method B. an instance method C. a static method or an instance method

Suppose x is 1. What is x after x -= 1? A. 0 B. 1 C. 2 D. -1 E. -2

The following program displays __________. public class Test { public static void main(String[] args) { String s = "Java"; StringBuilder buffer = new StringBuilder(s); change(s); System.out.println(s); } private static void change(String s) { s = s + " and HTML"; } } A. Java B. Java and HTML C. and HTML D. nothing is displayed

The reverse method is defined in this section. What is list1 after executing the following statements? int[] list1 = {1, 2, 3, 4, 5, 6}; int[] list2 = reverse(list1); A. list1 is 1 2 3 4 5 6 B. list1 is 6 5 4 3 2 1 C. list1 is 0 0 0 0 0 0 D. list1 is 6 6 6 6 6 6

To add 0.01 + 0.02 + ... + 1.00, what order should you use to add the numbers to get better accuracy? A. add 0.01, 0.02, ..., 1.00 in this order to a sum variable whose initial value is 0. B. add 1.00, 0.99, 0.98, ..., 0.02, 0.01 in this order to a sum variable whose initial value is 0.

What code may be filled in the blank without causing syntax or runtime errors: public class Test { java.util.Date date; public static void main(String[] args) { Test test = new Test(); System.out.println(_________________); } } A. test.date B. date C. test.date.toString() D. date.toString()

What is displayed on the console when running the following program? public class Test { public static void main(String[] args) { try { method(); System.out.println("After the method call"); } catch (NumberFormatException ex) { System.out.println("NumberFormatException"); } catch (RuntimeException ex) { System.out.println("RuntimeException"); } } static void method() { String s = "5.6"; Integer.parseInt(s); // Cause a NumberFormatException int i = 0; int y = 2 / i; System.out.println("Welcome to Java"); } } A. The program displays NumberFormatException. B. The program displays NumberFormatException followed by After the method call. C. The program displays NumberFormatException followed by RuntimeException. D. The program has a compile error. E. The program displays RuntimeException

What is sum after the following loop terminates? int sum = 0; int item = 0; do { item++; if (sum >= 4) continue; sum += item; } while (item < 5); A. 6 B. 7 C. 8 D. 9 E. 10

What is the output for the third statement in the main method? public class Foo { static int i = 0; static int j = 0; public static void main(String[] args) { int i = 2; int k = 3; { int j = 3; System.out.println("i + j is " + i + j); } k = i + j; System.out.println("k is " + k); System.out.println("j is " + j); } } A. j is 0 B. j is 1 C. j is 2 D. j is 3

What is the output of the following code? import javafx.beans.property.IntegerProperty; import javafx.beans.property.SimpleIntegerProperty; public class Test { public static void main(String[] args) { IntegerProperty d1 = new SimpleIntegerProperty(1); IntegerProperty d2 = new SimpleIntegerProperty(2); d1.bind(d2); System.out.print("d1 is " + d1.getValue() + " and d2 is " + d2.getValue()); d2.setValue(3); System.out.println(", d1 is " + d1.getValue() + " and d2 is " + d2.getValue()); } } A. d1 is 2 and d2 is 2, d1 is 3 and d2 is 3 B. d1 is 2 and d2 is 2, d1 is 2 and d2 is 3 C. d1 is 1 and d2 is 2, d1 is 1 and d2 is 3 D. d1 is 1 and d2 is 2, d1 is 3 and d2 is 3

What is the output of the following code? import javafx.beans.property.IntegerProperty; import javafx.beans.property.SimpleIntegerProperty; public class Test { public static void main(String[] args) { IntegerProperty d1 = new SimpleIntegerProperty(1); IntegerProperty d2 = new SimpleIntegerProperty(2); d1.bindBidirectional(d2); System.out.print("d1 is " + d1.getValue() + " and d2 is " + d2.getValue()); d1.setValue(3); System.out.println(", d1 is " + d1.getValue() + " and d2 is " + d2.getValue()); } } A. d1 is 2 and d2 is 2, d1 is 3 and d2 is 3 B. d1 is 2 and d2 is 2, d1 is 2 and d2 is 3 C. d1 is 1 and d2 is 2, d1 is 1 and d2 is 3 D. d1 is 1 and d2 is 2, d1 is 3 and d2 is 3

What is the output of the following code? public class Test { public static void main(String[] args) { java.math.BigInteger x = new java.math.BigInteger("3"); java.math.BigInteger y = new java.math.BigInteger("7"); x.add(y); System.out.println(x); } } A. 3 B. 4 C. 10 D. 11

What is the output of the following code? public class Test { public static void main(String[] args) { new Person().printPerson(); new Student().printPerson(); } } class Student extends Person { private String getInfo() { return "Student"; } } class Person { private String getInfo() { return "Person"; } public void printPerson() { System.out.println(getInfo()); } } A. Person Person B. Person Student C. Stduent Student D. Student Person

What is the output of the following code? public class Test { public static void main(String[] args) { String s1 = "Welcome to Java!"; String s2 = "Welcome to Java!"; if (s1 == s2) System.out.println("s1 and s2 reference to the same String object"); else System.out.println("s1 and s2 reference to different String objects"); } } A. s1 and s2 reference to the same String object B. s1 and s2 reference to different String objects

What is the output of the following code? public class Test { public static void main(String[] args) { String s1 = "Welcome to Java!"; String s2 = s1; if (s1 == s2) System.out.println("s1 and s2 reference to the same String object"); else System.out.println("s1 and s2 reference to different String objects"); } } A. s1 and s2 reference to the same String object B. s1 and s2 reference to different String objects

What is the output of the following code? public class Test { public static void main(String[] args) { String s1 = new String("Welcome to Java!"); String s2 = new String("Welcome to Java!"); if (s1.equals(s2)) System.out.println("s1 and s2 have the same contents"); else System.out.println("s1 and s2 have different contents"); } } A. s1 and s2 have the same contents B. s1 and s2 have different contents

What is the output of the following program? public class Test { public static void main(String[] args) { int[][] values = {{3, 4, 5, 1}, {33, 6, 1, 2}}; int v = values[0][0]; for (int[] list : values) for (int element : list) if (v > element) v = element; System.out.print(v); } } A. 1 B. 3 C. 5 D. 6 E. 33

What is the return value of "SELECT".substring(4, 4)? A. an empty string B. C C. T D. E

What is the value of myCount.count displayed? public class Test { public static void main(String[] args) { Count myCount = new Count(); int times = 0; for (int i=0; i<100; i++) increment(myCount, times); System.out.println( "myCount.count = " + myCount.count); System.out.println("times = "+ times); } public static void increment(Count c, int times) { c.count++; times++; } } class Count { int count; Count(int c) { count = c; } Count() { count = 1; } } A. 101 B. 100 C. 99 D. 98

What is the value of the following expression? true || true && false A. true B. false

What is y after the following statement is executed? x = 0; y = (x > 0) ? 10 : -10; A. -10 B. 0 C. 10 D. 20 E. Illegal expression

Which JDK command is correct to run a Java application in ByteCode.class? A. java ByteCode B. java ByteCode.class C. javac ByteCode.java D. javac ByteCode E. JAVAC ByteCode

Which class contains the method for checking whether a file exists? A. File B. PrintWriter C. Scanner D. System

Which code fragment would correctly identify the number of arguments passed via the command line to a Java application, excluding the name of the class that is being invoked? A. int count = args.length; B. int count = args.length - 1; C. int count = 0; while (args[count] != null) count ++; D. int count=0; while (!(args[count].equals(""))) count ++;

Which of the following can be placed in the blank line in the following code? public class Test { private int id; public void m1() { _____.id = 45; } } A. this B. Test

Which of the following should be defined as a void method? A. Write a method that prints integers from 1 to 100. B. Write a method that returns a random integer from 1 to 100. C. Write a method that checks whether current second is an integer from 1 to 100. D. Write a method that converts an uppercase letter to lowercase.

Which of the following statements are correct? I: File file = new File("input.txt"); try (Scanner input = new Scanner(file)) { String line = input.nextLine(); } II: try (File file = new File("input.txt"); Scanner input = new Scanner(file);) { String line = input.nextLine(); } III: File file; try (file = new File("input.txt"); Scanner input = new Scanner(file);) { String line = input.nextLine(); } IV: File file; Scanner input; try (file = new File("input.txt"); input = new Scanner(file);) { String line = input.nextLine(); } A. I B. II C. III D. IV

Which of the following statements is incorrect? A. Integer i = 4.5; B. Double i = 4.5; C. Object i = 4.5; D. Number i = 4.5;

Which of the following statements is preferred to create a string "Welcome to Java"? A. String s = "Welcome to Java"; B. String s = new String("Welcome to Java"); C. String s; s = "Welcome to Java"; D. String s; s = new String("Welcome to Java");

Which of these data types requires the most amount of memory? A. long B. int C. short D. byte

Which statements are most accurate regarding the following classes? class A { private int i; protected int j; } class B extends A { private int k; protected int m; } A. An object of B contains data fields i, j, k, m. B. An object of B contains data fields j, k, m. C. An object of B contains data fields j, m. D. An object of B contains data fields k, m.

Will the following program terminate? int balance = 10; while (true) { if (balance < 9) break; balance = balance - 9; } A. Yes B. No

You should add the static keyword in the place of ? in Line ________ in the following code: 1 public class Test { 2 private int age; 3 4 public ? int square(int n) { 5 return n * n; 6 } 7 8 public ? int getAge() { 9 } 10} A. in line 4 B. in line 8 C. in both line 4 and line 8 D. none

_______ is architecture-neutral A) Java B) C++ C) C D) Ada E) Pascal

________ is interpreted A) Java B) C++ C) C D) Ada E) Pascal

_________ is a simple but incomplete version of a method. A. A stub B. A main method C. A non-main method D. A method developed using top-down approach

_________ returns the last character in a StringBuilder variable named strBuf? A. strBuf.charAt(strBuf.length() - 1) B. strBuf.charAt(strBuf.capacity() - 1) C. StringBuilder.charAt(strBuf.length() - 1) D. StringBuilder.charAt(strBuf.capacity() - 1)

Math.sin(Math.PI) returns _______. A. 0.0 B. 1.0 C. 0.5 D. 0.4

A Note that Math.PI is 180 degrees

Analyze the following code: ArrayList<String> list = new ArrayList<String>(); list.add("Beijing"); list.add("Tokyo"); list.add("Shanghai"); list.set(3, "Hong Kong"); A. The last line in the code causes a runtime error because there is no element at index 3 in the array list. B. The last line in the code has a compile error because there is no element at index 3 in the array list. C. If you replace the last line by list.add(3, "Hong Kong"), the code will compile and run fine. D. If you replace the last line by list.add(4, "Hong Kong"), the code will compile and run fine.

A and C

Analyze the following code: class Test { private double i; public Test(double i) { this.t(); this.i = i; } public Test() { System.out.println("Default constructor"); this(1); } public void t() { System.out.println("Invoking t"); } } A. this.t() may be replaced by t(). B. this.i may be replaced by i. C. this(1) must be called before System.out.println("Default constructor"). D. this(1) must be replaced by this(1.0)

A and C

Suppose ArrayList x contains two strings [Beijing, Singapore]. Which of the following method will cause the list to become [Beijing]? A. x.remove("Singapore") B. x.remove(0) C. x.remove(1) D. x.remove(2)

A and C

To add two nodes node1 and node2 to the the first row in a GridPane pane, use ________. A. pane.add(node1, 0, 0); pane.add(node2, 1, 0); B. pane.add(node1, node2, 0); C. pane.addRow(0, node1, node2); D. pane.addRow(1, node1, node2); E. pane.add(node1, 0, 1); pane.add(node2, 1, 1);

A and C

To construct a Polygon with three points x1, y1, x2, y2, x3, and y3, use _________. A. new Polygon(x1, y1, x2, y2, x3, y3) B. new Polygon(x1, y2, x3, y1, y2, y3) C. Polygon polygon = new Polygon(); polygon.getPoints().addAll(x1, y1, x2, y2, x3, y3) D. Polygon polygon = new Polygon(); polygon.getPoints().addAll(x1, y2, x3, y1, y2, y3)

A and C

To construct a Polyline with three points x1, y1, x2, y2, x3, and y3, use _________. A. new Polyline(x1, y1, x2, y2, x3, y3) B. new Polyline(x1, y2, x3, y1, y2, y3) C. Polyline polyline = new Polygon(); polyline.getPoints().addAll(x1, y1, x2, y2, x3, y3) D. Polyline polyline = new Polygon(); polyline.getPoints().addAll(x1, y2, x3, y1, y2, y3)

A and C

Which method can be used to create an output object for file temp.txt? A. new PrintWriter("temp.txt") B. new PrintWriter(temp.txt) C. new PrintWriter(new File("temp.txt")) D. new PrintWriter(File("temp.txt"))

A and C

Which of the following are so called short-circuit operators? A. && B. & C. || D. |

A and C

Which of the following is equivalent to x != y? A. ! (x == y) B. x > y && x < y C. x > y || x < y D. x >= y || x <= y

A and C

Which of the following statements correctly sets the fill color of circle to black? A. circle.setFill(Color.BLACK); B. circle.setFill(Color.black); C. circle.setStyle("-fx-fill: black"); D. circle.setStyle("fill: black"); E. circle.setStyle("-fx-fill-color: black");

A and C

Suppose Character x = new Character('a'), __________________ returns true. A. x.equals(new Character('a')) B. x.compareToIgnoreCase('A') C. x.equalsIgnoreCase('A') D. x.equals('a') E. x.equals("a")

A and D

Which of the following are correct names for variables according to Java naming conventions? A. radius B. Radius C. RADIUS D. findArea E. FindArea

A and D

Which of the following statements are correct? A. char[][][] charArray = new char[2][2][]; B. char[2][2][] charArray = {'a', 'b'}; C. char[][][] charArray = {{'a', 'b'}, {'c', 'd'}, {'e', 'f'}}; D. char[][][] charArray = {{{'a', 'b'}, {'c', 'd'}, {'e', 'f'}}};

A and D

Which of the following statements are true? A. A class should describe a single entity and all the class operations should logically fit together to support a coherent purpose. B. A class should always contain a no-arg constructor. C. The constructors must always be public. D. The constructors may be protected

A and D

Which of the following is a constant, according to Java naming conventions? A. MAX_VALUE B. Test C. read D. ReadInt E. COUNT

A and E

___________ translates high-level language program into machine language program

A compiler

Every statement in Java ends with ________

A semicolon ( ; )

Suppose you enter 34.3, the ENTER key, 57.8, the ENTER key. Analyze the following code. 1 Scanner input = new Scanner(System.in); 2 double v1 = input.nextDouble(); 3 double v2 = input.nextDouble(); 4 String line = input.nextLine(); A. After line 2 is executed, v1 is 34.3. B. After line 3 is executed, v2 is 57.8. C. After line 4 is executed, line contains an empty string. D. After line 4 is executed, line is null. E. After line 4 is executed, line contains character "\n"

A, B and C

The _________ properties are defined in the javafx.scene.shape.Shape class. A. stroke B. strokeWidth C. fill D. centerX

A, B and C

Which of the following statements are correct? I: try (PrintWriter output = new PrintWriter("output.txt")) { output.println("Welcome to Java"); } II: try (PrintWriter output = new PrintWriter("output.txt");) { output.println("Welcome to Java"); } III: PrintWriter output; try (output = new PrintWriter("output.txt");) { output.println("Welcome to Java"); } IV: try (PrintWriter output = new PrintWriter("output.txt");) { output.println("Welcome to Java"); } finally { output.close(); } A. I B. II C. III D. IV

A, B and C

Which of the following statements are true? A. Use the private modifier to encapsulate data fields. B. Encapsulating data fields makes the program easy to maintain. C. Encapsulating data fields makes the program short. D. Encapsulating data fields helps prevent programming errors.

A, B and D

In JDK 1.5, analyze the following code. Line 1: Integer[] intArray = {1, 2, 3}; Line 2: int i = intArray[0] + intArray[1]; Line 3: int j = i + intArray[2]; Line 4: double d = intArray[0]; A. It is OK to assign 1, 2, 3 to an array of Integer objects in JDK 1.5. B. It is OK to automatically convert an Integer object to an int value in Line 2. C. It is OK to mix an int value with an Integer object in an expression in Line 3. D. Line 4 is OK. An int value from intArray[0] object is assigned to a double variable d

A, B, C and D

The GeometricObject and Circle classes are defined in this chapter. Analyze the following code. Which statements are correct? public class Test { public static void main(String[] args) { GeometricObject x = new Circle(3); GeometricObject y = (Circle)(x.clone()); System.out.println(x); System.out.println(y); } } A. The program has a compile error because the clone() method is protected in the Object class. B. After you override the clone() method and make it public in the Circle class, the problem can compile and run just fine, but y is null if Circle does not implement the Cloneable interface. C. To enable a Circle object to be cloned, the Circle class has to override the clone() method and implement the java.lang.Cloneable interface. D. If GeometricObject implements Cloneable and Circle overrides the clone() method, the clone() method will work fine to clone Circle objects

A, B, C and D

The _________ properties are defined in the javafx.scene.shape.Ellipse class. A. centerX B. centerY C. radiusX D. radiusY

A, B, C and D

The _________ properties are defined in the javafx.scene.shape.Line class. A. x1 B. x2 C. y1 D. y2 E. strikethrough

A, B, C and D

To check if a string s contains the prefix "Java", you may write A. if (s.startsWith("Java")) ... B. if (s.indexOf("Java") == 0) ... C. if (s.substring(0, 4).equals("Java")) ... D. if (s.charAt(0) == 'J' && s.charAt(1) == 'a' && s.charAt(2) == 'v' && s.charAt(3) == 'a') ...

A, B, C and D

What are the reasons to create an instance of the File class? A. To determine whether the file exists. B. To obtain the properties of the file such as whether the file can be read, written, or is hidden. C. To rename the file. D. To delete the file. E. To read/write data from/to a file

A, B, C and D

Which of the following is poor design? A. A data field is derived from other data fields in the same class. B. A method must be invoked after/before invoking another method in the same class. C. A method is an instance method, but it does not reference any instance data fields or invoke instance methods. D. A parameter is passed from a constructor to initialize a static data field

A, B, C and D

Which of the following is the correct header of the main method? A. public static void main(String[] args) B. public static void main(String args[]) C. public static void main(String[] x) D. public static void main(String x[]) E. static void main(String[] args)

A, B, C and D

Which of the following is true? A. You can add characters into a string buffer. B. You can delete characters into a string buffer. C. You can reverse the characters in a string buffer. D. The capacity of a string buffer can be automatically adjusted

A, B, C and D

Which of the following statements are correct to create a FlowPane? A. new FlowPane() B. new FlowPane(4, 5) C. new FlowPane(Orientation.VERTICAL); D. new FlowPane(4, 5, Orientation.VERTICAL);

A, B, C and D

Which of the following statements are correct? A. A Color object is immutable. B. A Font object is immutable. C. You cannot change the contents in a Color object once it is created. D. You cannot change the contents in a Font object once it is created.

A, B, C and D

Which of the following statements are correct? A. Every subclass of Node has a no-arg constructor. B. Circle is a subclass of Node. C. Button is a subclass of Node. D. Pane is a subclass of Node. E. Scene is a subclass on Node.

A, B, C and D

Which of the following statements are correct? A. When creating a Random object, you have to specify the seed or use the default seed. B. If two Random objects have the same seed, the sequence of the random numbers obtained from these two objects are identical. C. The nextInt() method in the Random class returns the next random int value. D. The nextDouble() method in the Random class returns the next random double value.

A, B, C and D

Which of the following statements are true? A. Local variables do not have default values. B. Data fields have default values. C. A variable of a primitive type holds a value of the primitive type. D. A variable of a reference type holds a reference to where an object is stored in the memory. E. You may assign an int value to a reference variable.

A, B, C and D

Which of the following statements are true? A. Override the methods equals and toString defined in the Object class whenever possible. B. Override the hashCode method whenever the equals method is overridden. By contract, two equal objects must have the same hash code. C. A public default no-arg constructor is assumed if no constructors are defined explicitly. D. You should follow standard Java programming style and naming conventions. Choose informative names for classes, data fields, and methods

A, B, C and D

Which of the following statements are true? A. You use the keyword throws to declare exceptions in the method heading. B. A method may declare to throw multiple exceptions. C. To throw an exception, use the key word throw. D. If a checked exception occurs in a method, it must be either caught or declared to be thrown from the method

A, B, C and D

Which of the following statements correctly creates an ImageView object? A. new ImageView("http://www.cs.armstrong.edu/liang/image/us.gif"); B. new ImageView(new Image("http://www.cs.armstrong.edu/liang/image/us.gif")); C. new ImageView("image/us.gif"); D. new ImageView(new Image("image/us.gif"));

A, B, C and D

__________ returns a string. A. String.valueOf(123) B. String.valueOf(12.53) C. String.valueOf(false) D. String.valueOf(new char[]{'a', 'b', 'c'})

A, B, C and D

Which of the following are valid specifiers for the printf statement? A. %4c B. %10b C. %6d D. %8.2d E. %10.2e

A, B, C and E

The StringBuilder methods _____________ not only change the contents of a string buffer, but also returns a reference to the string buffer. A. delete B. append C. insert D. reverse E. replace

A, B, C, D and E

The _________ properties are defined in the javafx.scene.shape.Rectangle class. A. width B. x C. y D. height E. arcWidth

A, B, C, D and E

The _________ properties are defined in the javafx.scene.text.Text class. A. text B. x C. y D. underline E. strikethrough

A, B, C, D and E

Which of the following classes are immutable? A. Integer B. Double C. BigInteger D. BigDecimal E. String

A, B, C, D and E

Which of the following statements are true? A. Inheritance models the is-a relationship between two classes. B. A strong is-a relationship describes a direct inheritance relationship between two classes. C. A weak is-a relationship describes that a class has certain properties. D. A strong is-a relationship can be represented using class inheritance. E. A weak is-a relationship can be represented using interfaces

A, B, C, D and E

Which of the following statements are true? A. To override a method, the method must be defined in the subclass using the same signature and compatible return type as in its superclass. B. Overloading a method is to provide more than one method with the same name but with different signatures to distinguish them. C. It is a compile error if two methods differ only in return type in the same class. D. A private method cannot be overridden. If a method defined in a subclass is private in its superclass, the two methods are completely unrelated. E. A static method cannot be overridden. If a static method defined in the superclass is redefined in a subclass, the method defined in the superclass is hidden

A, B, C, D and E

Which of the following statements correctly creates a Font object? A. new Font(34); B. new Font("Times", 34); C. Font.font("Times", 34); D. Font.font("Times", FontWeight.NORMAL, 34); E. Font.font("Times", FontWeight.NORMAL, FontPosture.ITALIC, 34);

A, B, C, D and E

Suppose s1 and s2 are two strings. Which of the following statements or expressions is incorrect? A. String s3 = s1 - s2; B. boolean b = s1.compareTo(s2); C. char c = s1[0]; D. char c = s1.charAt(s1.length());

A, B, C, and D

Suppose you write the code to display "Cannot get a driver's license" if age is less than 16 and "Can get a driver's license" if age is greater than or equal to 16. Which of the following code is correct? I: if (age < 16) System.out.println("Cannot get a driver's license"); if (age >= 16) System.out.println("Can get a driver's license"); II: if (age < 16) System.out.println("Cannot get a driver's license"); else System.out.println("Can get a driver's license"); III: if (age < 16) System.out.println("Cannot get a driver's license"); else if (age >= 16) System.out.println("Can get a driver's license"); IV: if (age < 16) System.out.println("Cannot get a driver's license"); else if (age > 16) System.out.println("Can get a driver's license"); else if (age == 16) System.out.println("Can get a driver's license"); A. I B. II C. III D. IV

A, B, C, and D

What is the possible output from System.out.println((int)(Math.random( ) * 4))? A. 0 B. 1 C. 2 D. 3 E. 4

A, B, C, and D

Which of the following are the reserved words? A. public B. static C. void D. class

A, B, C, and D

Which of the following are the same as 1545.534? A. 1.545534e+3 B. 0.1545534e+4 C. 1545534.0e-3 D. 154553.4e-2

A, B, C, and D

Which of the following statements are true about an immutable object? A. The contents of an immutable object cannot be modified. B. All properties of an immutable object must be private. C. All properties of an immutable object must be of primitive types. D. An object type property in an immutable object must also be immutable. E. An immutable object contains no mutator methods

A, B, D and E

Suppose a JavaFX class has a binding property named weight of the type DoubleProperty. By convention, which of the following methods are defined in the class? A. public double getWeight() B. public void setWeight(double v) C. public DoubleProperty weightProperty() D. public double weightProperty() E. public DoubleProperty WeightProperty()

A, B, and C

Which of the following statements are correct to invoke the printMax method in Listing 7.5 in the textbook? A. printMax(1, 2, 2, 1, 4); B. printMax(new double[]{1, 2, 3}); C. printMax(1.0, 2.0, 2.0, 1.0, 4.0); D. printMax(new int[]{1, 2, 3});

A, B, and C

Which of the following statements are true? A. (x > 0 && x < 10) is same as ((x > 0) && (x < 10)) B. (x > 0 || x < 10) is same as ((x > 0) || (x < 10)) C. (x > 0 || x < 10 && y < 0) is same as (x > 0 || (x < 10 && y < 0)) D. (x > 0 || x < 10 && y < 0) is same as ((x > 0 || x < 10) && y < 0

A, B, and C

To check if a string s contains the suffix "Java", you may write A. if (s.endsWith("Java")) ... B. if (s.lastIndexOf("Java") >= 0) ... C. if (s.substring(s.length() - 4).equals("Java")) ... D. if (s.substring(s.length() - 5).equals("Java")) ... E. if (s.charAt(s.length() - 4) == 'J' && s.charAt(s.length() - 3) == 'a' && s.charAt(s.length() - 2) == 'v' && s.charAt(s.length() - 1) == 'a') ...

A, C and E

Which of the following statements are true? A. A method can be overloaded in the same class. B. A method can be overridden in the same class. C. If a method overloads another method, these two methods must have the same signature. D. If a method overrides another method, these two methods must have the same signature. E. A method in a subclass can overload a method in the superclass

A, D and E

Which of the Boolean expressions below is incorrect? A. (true) && (3 => 4) B. !(x > 0) && (x > 0) C. (x > 0) || (x < 0) D. (x != 0) || (x = 0) E. (-10 < x < 0)

A, D, and E

Assume int[] scores = {1, 20, 30, 40, 50}, what is the output of System.out.println(java.util.Arrays.toString(scores))? A. {1, 20, 30, 40, 50} B. [1, 20, 30, 40, 50] C. {1 20 30 40 50} D. [1 20 30 40 50]

Assume int[][] x = {{1, 2}, {3, 4, 5}, {5, 6, 5, 9}}, what are x[0].length, x[1].length, and x[2].length? A. 2, 3, and 3 B. 2, 3, and 4 C. 3, 3, and 3 D. 3, 3, and 4 E. 2, 2, and 2

Assume s is "ABCABC", the method __________ returns an array of characters. A. toChars(s) B. s.toCharArray() C. String.toChars() D. String.toCharArray() E. s.toChars()

Assume x = 4 and y = 5, which of the following is true? A. !(x == 4) ^ y != 5 B. x != 4 ^ y == 5 C. x == 5 ^ y == 4 D. x != 5 ^ y != 4

Assume x = 4 and y = 5, which of the following is true? A. x < 5 && y < 5 B. x < 5 || y < 5 C. x > 5 && y > 5 D. x > 5 || y > 5

A Java character is stored in __________. A. one byte B. two bytes C. three bytes D. four bytes

A method must declare to throw ________. A. unchecked exceptions B. checked exceptions C. Error D. RuntimeException

"abc".compareTo("aba") returns ___________. A. 1 B. 2 C. -1 D. -2 E. 0

'3' - '2' + 'm' / 'n' is ______. A. 0 B. 1 C. 2 D. 3

(int)('a' + Math.random() * ('z' - 'a' + 1)) returns a random number __________. A. between 0 and (int)'z' B. between (int)'a' and (int)'z' C. between 'a' and 'z' D. between 'a' and 'y'

Analyze the following code. // Program 1: public class Test { public static void main(String[] args) { Object a1 = new A(); Object a2 = new A(); System.out.println(a1.equals(a2)); } } class A { int x; public boolean equals(A a) { return this.x == a.x; } } // Program 2: public class Test { public static void main(String[] args) { A a1 = new A(); A a2 = new A(); System.out.println(a1.equals(a2)); } } class A { int x; public boolean equals(A a) { return this.x == a.x; } } A. Program 1 displays true and Program 2 displays true B. Program 1 displays false and Program 2 displays true C. Program 1 displays true and Program 2 displays false D. Program 1 displays false and Program 2 displays false

Analyze the following code. boolean even = false; if (even) { System.out.println("It is even!"); } A. The code displays It is even! B. The code displays nothing. C. The code is wrong. You should replace if (even) with if (even == true). D. The code is wrong. You should replace if (even) with if (even = true)

Analyze the following code. class TempClass { int i; public void TempClass(int j) { int i = j; } } public class C { public static void main(String[] args) { TempClass temp = new TempClass(2); } } A. The program has a compile error because TempClass does not have a default constructor. B. The program has a compile error because TempClass does not have a constructor with an int argument. C. The program compiles fine, but it does not run because class C is not public. D. The program compiles and runs fine

Analyze the following code. public class Test { public static void main(String[] args) { System.out.println(max(1, 2)); } public static double max(int num1, double num2) { System.out.println("max(int, double) is invoked"); if (num1 > num2) return num1; else return num2; } public static double max(double num1, int num2) { System.out.println("max(double, int) is invoked"); if (num1 > num2) return num1; else return num2; } } A. The program cannot compile because you cannot have the print statement in a non-void method. B. The program cannot compile because the compiler cannot determine which max method should be invoked. C. The program runs and prints 2 followed by "max(int, double)" is invoked. D. The program runs and prints 2 followed by "max(double, int)" is invoked. E. The program runs and prints "max(int, double) is invoked" followed by 2

Analyze the following code. public class Test { public static void main(String[] args) { int n = 2; xMethod(n); System.out.println("n is " + n); } void xMethod(int n) { n++; } } A. The code has a compile error because xMethod does not return a value. B. The code has a compile error because xMethod is not declared static. C. The code prints n is 1. D. The code prints n is 2. E. The code prints n is 3.

Analyze the following code: class Circle { private double radius; public Circle(double radius) { radius = radius; } } A. The program has a compile error because it does not have a main method. B. The program will compile, but you cannot create an object of Circle with a specified radius. The object will always have radius 0. C. The program has a compile error because you cannot assign radius to radius. D. The program does not compile because Circle does not have a default constructor

Analyze the following code: class Test { public static void main(String[] args) { System.out.println(xmethod(5)); } public static int xmethod(int n, long t) { System.out.println("int"); return n; } public static long xmethod(long n) { System.out.println("long"); return n; } } A. The program displays int followed by 5. B. The program displays long followed by 5. C. The program runs fine but displays things other than 5. D. The program does not compile because the compiler cannot distinguish which xmethod to invoke.

Analyze the following code: import javafx.application.Application; import javafx.scene.Scene; import javafx.scene.layout.HBox; import javafx.scene.layout.Pane; import javafx.geometry.Insets; import javafx.stage.Stage; import javafx.scene.image.Image; import javafx.scene.image.ImageView; public class Test extends Application { @Override // Override the start method in the Application class public void start(Stage primaryStage) { // Create a pane to hold the image views Pane pane = new HBox(10); pane.setPadding(new Insets(5, 5, 5, 5)); Image image = new Image("www.cs.armstrong.edu/liang/image/us.gif"); pane.getChildren().addAll(new ImageView(image), new ImageView(image)); // Create a scene and place it in the stage Scene scene = new Scene(pane); primaryStage.setTitle("ShowImage"); // Set the stage title primaryStage.setScene(scene); // Place the scene in the stage primaryStage.show(); // Display the stage } /** * The main method is only needed for the IDE with limited * JavaFX support. Not needed for running from the command line. */ public static void main(String[] args) { launch(args); } } A. The program runs fine and displays two images. B. new Image("www.cs.armstrong.edu/liang/image/us.gif") must be replaced by new Image("http://www.cs.armstrong.edu/liang/image/us.gif"). C. The image object cannot be shared by two ImageViews. D. The addAll method needs to be replaced by the add method

Analyze the following code: public class Test { public static void main(String[] args) { new B(); } } class A { int i = 7; public A() { System.out.println("i from A is " + i); } public void setI(int i) { this.i = 2 * i; } } class B extends A { public B() { setI(20); // System.out.println("i from B is " + i); } @Override public void setI(int i) { this.i = 3 * i; } } A. The constructor of class A is not called. B. The constructor of class A is called and it displays "i from A is 7". C. The constructor of class A is called and it displays "i from A is 40". D. The constructor of class A is called and it displays "i from A is 60"

Analyze the following code: public class Test { public static void main(String[] args) { try { int zero = 0; int y = 2/zero; try { String s = "5.6"; Integer.parseInt(s); // Cause a NumberFormatException } catch(Exception e) { } } catch(RuntimeException e) { System.out.println(e); } } } A. A try-catch block cannot be embedded inside another try-catch block. B. A good programming practice is to avoid nesting try-catch blocks, because nesting makes programs difficult to read. You can rewrite the program using only one try-catch block. C. The program has a compile error because Exception appears before RuntimeException. D. None of the above.

Analyze the following code: public class Test { public static void main(String[] args) { int[] x = {1, 2, 3, 4}; int[] y = x; x = new int[2]; for (int i = 0; i < x.length; i++) System.out.print(x[i] + " "); } } A. The program displays 1 2 3 4 B. The program displays 0 0 C. The program displays 0 0 3 4 D. The program displays 0 0 0 0

The getValue() method is overridden in two ways. Which one is correct? I: public class Test { public static void main(String[] args) { A a = new A(); System.out.println(a.getValue()); } } class B { public String getValue() { return "Any object"; } } class A extends B { public Object getValue() { return "A string"; } } II: public class Test { public static void main(String[] args) { A a = new A(); System.out.println(a.getValue()); } } class B { public Object getValue() { return "Any object"; } } class A extends B { public String getValue() { return "A string"; } }

The java.util.Calendar and java.util.GregorianCalendar classes are introduced in Chapter 11. Analyze the following code. Which of the following statements is correct? 1. import java.util.*; 2. public class Test { 3. public static void main(String[] args) { 4. Calendar[] calendars = new Calendar[10]; 5. calendars[0] = new Calendar(); 6. calendars[1] = new GregorianCalendar(); 7. } 8. } A. The program has a compile error on Line 4 because java.util.Calendar is an abstract class. B. The program has a compile error on Line 5 because java.util.Calendar is an abstract class. C. The program has a compile error on Line 6 because Calendar[1] is not of a GregorianCalendar type. D. The program has no compile errors

The reverse method is defined in the textbook. What is list1 after executing the following statements? int[] list1 = {1, 2, 3, 4, 5, 6}; list1 = reverse(list1); A. list1 is 1 2 3 4 5 6 B. list1 is 6 5 4 3 2 1 C. list1 is 0 0 0 0 0 0 D. list1 is 6 6 6 6 6 6

The visibility of these modifiers increases in this order: A. private, protected, none (if no modifier is used), and public. B. private, none (if no modifier is used), protected, and public. C. none (if no modifier is used), private, protected, and public. D. none (if no modifier is used), protected, private, and public

To check whether a char variable ch is an uppercase letter, you write ___________. A. (ch >= 'A' && ch >= 'Z') B. (ch >= 'A' && ch <= 'Z') C. (ch >= 'A' || ch <= 'Z') D. ('A' <= ch <= 'Z')

Use the selectionSort method presented in this section to answer this question. What is list1 after executing the following statements? double[] list1 = {3.1, 3.1, 2.5, 6.4}; selectionSort(list1); A. list1 is 3.1, 3.1, 2.5, 6.4 B. list1 is 2.5 3.1, 3.1, 6.4 C. list1 is 6.4, 3.1, 3.1, 2.5 D. list1 is 3.1, 2.5, 3.1, 6.4

What exception type does the following program throw? public class Test { public static void main(String[] args) { int[] list = new int[5]; System.out.println(list[5]); } } A. ArithmeticException B. ArrayIndexOutOfBoundsException C. StringIndexOutOfBoundsException D. ClassCastException E. No exception

What is displayed by the following code? String[] tokens = "A,B;C;D".split("[,;]"); for (int i = 0; i < tokens.length; i++) System.out.print(tokens[i] + " "); A. A,B;C;D B. A B C D C. A B C;D D. A B;C;D

What is displayed on the console when running the following program? public class Test { public static void main (String[] args) { try { System.out.println("Welcome to Java"); return; } finally { System.out.println("The finally clause is executed"); } } } A. Welcome to Java B. Welcome to Java followed by The finally clause is executed in the next line C. The finally clause is executed D. None of the above

What is displayed on the console when running the following program? public class Test { public static void main (String[] args) { try { System.out.println("Welcome to Java"); } finally { System.out.println("The finally clause is executed"); } } } A. Welcome to Java B. Welcome to Java followed by The finally clause is executed in the next line C. The finally clause is executed D. None of the above

What is displayed on the console when running the following program? public class Test { public static void main(String[] args) { try { System.out.println("Welcome to Java"); int i = 0; int y = 2 / i; System.out.println("Welcome to HTML"); } finally { System.out.println("The finally clause is executed"); } } } A. Welcome to Java, then an error message. B. Welcome to Java followed by The finally clause is executed in the next line, then an error message. C. The program displays three lines: Welcome to Java, Welcome to HTML, The finally clause is executed, then an error message. D. None of the above.

What is displayed on the console when running the following program? public class Test { public static void main(String[] args) { try { System.out.println("Welcome to Java"); int i = 0; int y = 2/i; System.out.println("Welcome to Java"); } catch (RuntimeException ex) { System.out.println("Welcome to Java"); } finally { System.out.println("End of the block"); } } } A. The program displays Welcome to Java three times followed by End of the block. B. The program displays Welcome to Java two times followed by End of the block. C. The program displays Welcome to Java three times. D. The program displays Welcome to Java two times

What is output of the following code: public class Test { public static void main(String[] args) { int[] x = {120, 200, 016}; for (int i = 0; i < x.length; i++) System.out.print(x[i] + " "); } } A. 120 200 16 B. 120 200 14 C. 120 200 20 D. 016 is a compile error. It should be written as 16

What is sum after the following loop terminates? int sum = 0; int item = 0; do { item++; sum += item; if (sum > 4) break; } while (item < 5); A. 5 B. 6 C. 7 D. 8 E. 9

What is the number of iterations in the following loop? for (int i = 1; i <= n; i++) { // iteration } A. 2*n B. n C. n - 1 D. n + 1

What is the output after the following loop terminates? int number = 25; int i; boolean isPrime = true; for (i = 2; i < number; i++) { if (number % i == 0) { isPrime = false; break; } } System.out.println("i is " + i + " isPrime is " + isPrime); A. i is 5 isPrime is true B. i is 5 isPrime is false C. i is 6 isPrime is true D. i is 6 isPrime is false

What is the output of the following code? ArrayList<String> list = new ArrayList<String>(); String s1 = new String("Java"); String s2 = new String("Java"); list.add(s1); list.add(s2); System.out.println((list.get(0) == list.get(1)) + " " + (list.get(0)).equals(list.get(1))); A. true false B. false true C. true true D. false false

What is the output of the following code? boolean even = false; System.out.println((even ? "true" : "false")); A. true B. false C. nothing D. true false

What is the output of the following code? double[] myList = {1, 5, 5, 5, 5, 1}; double max = myList[0]; int indexOfMax = 0; for (int i = 1; i < myList.length; i++) { if (myList[i] > max) { max = myList[i]; indexOfMax = i; } } System.out.println(indexOfMax); A. 0 B. 1 C. 2 D. 3 E. 4

What is the output of the following code? int x = 0; if (x < 4) { x = x + 1; } System.out.println("x is " + x); A. x is 0 B. x is 1 C. x is 2 D. x is 3 E. x is 4

What is the output of the following code? public class Test { public static void main(String[] args) { new Person().printPerson(); new Student().printPerson(); } } class Student extends Person { @Override public String getInfo() { return "Student"; } } class Person { public String getInfo() { return "Person"; } public void printPerson() { System.out.println(getInfo()); } } A. Person Person B. Person Student C. Stduent Student D. Student Person

What is the output of the following code? public class Test { public static void main(String[] args) { String s1 = new String("Welcome to Java!"); String s2 = new String("Welcome to Java!"); if (s1 == s2) System.out.println("s1 and s2 reference to the same String object"); else System.out.println("s1 and s2 reference to different String objects"); } } A. s1 and s2 reference to the same String object B. s1 and s2 reference to different String objects

What is the output of the following code? public class Test { public static void main(String[] args) { String s1 = new String("Welcome to Java"); String s2 = s1; s1 += "and Welcome to HTML"; if (s1 == s2) System.out.println("s1 and s2 reference to the same String object"); else System.out.println("s1 and s2 reference to different String objects"); } } A. s1 and s2 reference to the same String object B. s1 and s2 reference to different String objects

What is the output of the following code? public class Test5 { public static void main(String[] args) { int[][] matrix = {{1, 2, 3, 4}, {4, 5, 6, 7}, {8, 9, 10, 11}, {12, 13, 14, 15}}; for (int i = 0; i < 4; i++) System.out.print(matrix[1][i] + " "); } } A. 1 2 3 4 B. 4 5 6 7 C. 1 3 8 12 D. 2 5 9 13 E. 3 6 10 14

What is the output of the following program? import java.util.Date; public class Test { public static void main(String[] args) { Date date = new Date(1234567); m1(date); System.out.print(date.getTime() + " "); m2(date); System.out.println(date.getTime()); } public static void m1(Date date) { date = new Date(7654321); } public static void m2(Date date) { date.setTime(7654321); } } A. 1234567 1234567 B. 1234567 7654321 C. 7654321 1234567 D. 7654321 7654321

What is the output of the second println statement in the main method? public class Foo { int i; static int s; public static void main(String[] args) { Foo f1 = new Foo(); System.out.println("f1.i is " + f1.i + " f1.s is " + f1.s); Foo f2 = new Foo(); System.out.println("f2.i is " + f2.i + " f2.s is " + f2.s); Foo f3 = new Foo(); System.out.println("f3.i is " + f3.i + " f3.s is " + f3.s); } public Foo() { i++; s++; } } A. f2.i is 1 f2.s is 1 B. f2.i is 1 f2.s is 2 C. f2.i is 2 f2.s is 2 D. f2.i is 2 f2.s is 1

What is the return value of "SELECT".substring(0, 5)? A. "SELECT" B. "SELEC" C. "SELE" D. "ELECT"

What is wrong in the following program? public class Test { public static void main (String[] args) { try { System.out.println("Welcome to Java"); } } } A. You cannot have a try block without a catch block. B. You cannot have a try block without a catch block or a finally block. C. A method call that does not declare exceptions cannot be placed inside a try block. D. Nothing is wrong

What is x after the following statements? int x = 1; x *= x + 1; A. x is 1. B. x is 2. C. x is 3. D. x is 4.

What is y after the following for loop statement is executed? int y = 0; for (int i = 0; i < 10; ++i) { y += 1; } A. 9 B. 10 C. 11 D. 12

What is y after the following switch statement is executed? int x = 3; int y = 4; switch (x + 3) { case 6: y = 0; case 7: y = 1; default: y += 1; } A. 1 B. 2 C. 3 D. 4 E. 0

What is y displayed? public class Test { public static void main(String[] args) { int x = 1; int y = x + x++; System.out.println("y is " + y); } } A. y is 1. B. y is 2. C. y is 3. D. y is 4.

When you invoke a method with a parameter, the value of the argument is passed to the parameter. This is referred to as _________. A. method invocation B. pass by value C. pass by reference D. pass by name

Which class do you use to write data into a text file? A. File B. PrintWriter C. Scanner D. System

Which correctly creates an array of five empty Strings? A. String[] a = new String [5]; B. String[] a = {"", "", "", "", ""}; C. String[5] a; D. String[ ] a = new String [5]; for (int i = 0; i < 5; a[i++] = null);

Which method can be used to read a whole line from the file? A. next B. nextLine C. nextInt D. nextDouble

Which method can be used to write data? A. close B. print C. exist D. rename

Which of the following are Java keywords? A. instanceOf B. instanceof C. cast D. casting

Which of the following expression results in 45.37? A. (int)(45.378 * 100) / 100 B. (int)(45.378 * 100) / 100.0 C. (int)(45.378 * 100 / 100) D. (int)(45.378) * 100 / 100.0

Which of the following is not an advantage of Java exception handling? A. Java separates exception handling from normal processing tasks. B. Exception handling improves performance. C. Exception handling makes it possible for the caller's caller to handle the exception. D. Exception handling simplifies programming because the error-reporting and error-handling code can be placed at the catch block

Which of the following is the correct expression that evaluates to true if the number x is between 1 and 100 or the number is negative? A. 1 < x < 100 && x < 0 B. ((x < 100) && (x > 1)) || (x < 0) C. ((x < 100) && (x > 1)) && (x < 0) D. (1 > x > 100) || (x < 0)

Which of the following is the correct statement to return a string from an array a of characters? A. toString(a) B. new String(a) C. convertToString(a) D. String.toString(a)

Which of the following returns the path separator character? A. File.pathSeparator B. File.pathSeparatorChar C. File.separator D. File.separatorChar E. None of the above

Which of the following statement prints smith\exam1\test.txt? A. System.out.println("smith\exam1\test.txt"); B. System.out.println("smith\\exam1\\test.txt"); C. System.out.println("smith\"exam1\"test.txt"); D. System.out.println("smith"\exam1"\test.txt");

Which of the following statements are the same? (A) x -= x + 4 (B) x = x + 4 - x (C) x = x - (x + 4) A. (A) and (B) are the same B. (A) and (C) are the same C. (B) and (C) are the same D. (A), (B), and (C) are the same

Which of the following statements creates an instance of File on Window for the file c:\temp.txt? A. new File("c:\temp.txt") B. new File("c:\\temp.txt") C. new File("c:/temp.txt") D. new File("c://temp.txt")

Which of the following statements is correct to display Welcome to Java on the console? A. System.out.println('Welcome to Java'); B. System.out.println("Welcome to Java"); C. System.println('Welcome to Java'); D. System.out.println('Welcome to Java"); E. System.out.println("Welcome to Java');

Which of the following statements is correct? A. Every line in a program must end with a semicolon. B. Every statement in a program must end with a semicolon. C. Every comment line must end with a semicolon. D. Every method must end with a semicolon. E. Every class must end with a semicolon.

Which statements are most accurate regarding the following classes? class A { private int i; protected int j; } class B extends A { private int k; protected int m; // some methods omitted } A. In the class B, an instance method can only access i, j, k, m. B. In the class B, an instance method can only access j, k, m. C. In the class B, an instance method can only access j, m. D. In the class B, an instance method can only access k, m.

Will System.out.println((char)4) display 4? A. Yes B. No

Will the following program terminate? int balance = 10; while (true) { if (balance < 9) continue; balance = balance - 9; } A. Yes B. No

_________ is to implement one method in the structure chart at a time from the top to the bottom. A. Bottom-up approach B. Top-down approach C. Bottom-up and top-down approach D. Stepwise refinement

Math.asin(0.5) returns _______. A. 30 B. Math.toRadians(30) C. Math.PI / 4 D. Math.PI / 2

B Math.asin returns an angle in radians

According to Java naming convention, which of the following names can be variables? A. FindArea B. findArea C. totalLength D. TOTAL_LENGTH E. class

B and C

Assume java.util.Date[] dates = new java.util.Date[10], which of the following statements are true? A. dates is null. B. dates[0] is null. C. dates = new java.util.Date[5] is fine, which assigns a new array to dates. D. dates = new Date() is fine, which creates a new Date object and assigns to dates

B and C

Which of the following is correct? A. String[] list = new String{"red", "yellow", "green"}; B. String[] list = new String[]{"red", "yellow", "green"}; C. String[] list = {"red", "yellow", "green"}; D. String list = {"red", "yellow", "green"}; E. String list = new String{"red", "yellow", "green"};

B and C

Which of the following statements is valid? A. int i = new int(30); B. double d[] = new double[30]; C. int[] i = {3, 4, 3, 2}; D. char[] c = new char(); E. char[] c = new char[4]{'a', 'b', 'c', 'd'};

B and C

Analyze the following code: public class Test { public static void main(String[] args) { A a = new A(); a.print(); } } class A { String s; A(String s) { this.s = s; } void print() { System.out.println(s); } } A. The program has a compile error because class A is not a public class. B. The program has a compile error because class A does not have a default constructor. C. The program compiles and runs fine and prints nothing. D. The program would compile and run if you change A a = new A() to A a = new A("5")

B and D

Analyze the following code: public class Test1 { public Object max(Object o1, Object o2) { if ((Comparable)o1.compareTo(o2) >= 0) { return o1; } else { return o2; } } } A. The program has a compile error because Test1 does not have a main method. B. The program has a compile error because o1 is an Object instance and it does not have the compareTo method. C. The program has a compile error because you cannot cast an Object instance o1 into Comparable. D. The program would compile if ((Comparable)o1.compareTo(o2) >= 0) is replaced by (((Comparable)o1).compareTo(o2) >= 0)

B and D

Assume p is a Polygon, to add a point (4, 5) into p, use _______. A. p.getPoints().add(4); p.getPoints().add(5); B. p.getPoints().add(4.0); p.getPoints().add(5.0); C. p.getPoints().addAll(4, 5); D. p.getPoints().addAll(4.0, 5.0);

B and D

Suppose A is an interface, B is a concrete class with a no-arg constructor that implements A. Which of the following is correct? A. A a = new A(); B. A a = new B(); C. B b = new A(); D. B b = new B();

B and D

Which of the following statement is most accurate? A. A reference variable is an object. B. A reference variable refers to an object. C. An object may contain other objects. D. An object may contain the references of other objects.

B and D

Analyze the following code. class Test { public static void main(String[] args) { StringBuilder strBuf = new StringBuilder(4); strBuf.append("ABCDE"); System.out.println("What's strBuf.charAt(5)? " + strBuf.charAt(5)); } } A. The program has a compile error because you cannot specify initial capacity in the StringBuilder constructor. B. The program has a runtime error because because the buffer's capacity is 4, but five characters "ABCDE" are appended into the buffer. C. The program has a runtime error because the length of the string in the buffer is 5 after "ABCDE" is appended into the buffer. Therefore, strBuf.charAt(5) is out of range. D. The program compiles and runs fine.

Analyze the following code. int[] list = new int[5]; list = new int[6]; A. The code has compile errors because the variable list cannot be changed once it is assigned. B. The code has runtime errors because the variable list cannot be changed once it is assigned. C. The code can compile and run fine. The second line assigns a new array to list. D. The code has compile errors because you cannot assign a different size array to list

Analyze the following code. public class Test { public static void main(String[] args) { int[] x = new int[3]; System.out.println("x[0] is " + x[0]); } } A. The program has a compile error because the size of the array wasn't specified when declaring the array. B. The program has a runtime error because the array elements are not initialized. C. The program runs fine and displays x[0] is 0. D. The program has a runtime error because the array element x[0] is not defined.

Analyze the following code. Which of the following statements is correct? public class Test { public static void main(String[] args) { Number x = new Integer(3); System.out.println(x.intValue()); System.out.println(x.compareTo(new Integer(4))); } } A. The program has a compile error because an Integer instance cannot be assigned to a Number variable. B. The program has a compile error because intValue is an abstract method in Number. C. The program has a compile error because x does not have the compareTo method. D. The program compiles and runs fine

Analyze the following code: Double[] array = {1, 2, 3}; ArrayList<Double> list = new ArrayList<>(Arrays.asList(array)); System.out.println(list); A. The code is correct and displays [1, 2, 3]. B. The code is correct and displays [1.0, 2.0, 3.0]. C. The code has a compile error because an integer such as 1 is automatically converted into an Integer object, but the array element type is Double. D. The code has a compile error because asList(array) requires that the array elements are objects

Analyze the following code: Integer[] c = {3, 5}; java.util.Collections.shuffle(c); System.out.println(java.util.Arrays.toString(c)); A. The code is correct and displays [3, 5]. B. The code is correct and displays [5, 3]. C. The code has a compile error on Collections.shuffle(c). c cannot be an array. D. The code has a compile error on Integer[] c = {3, 5}

Analyze the following code: double[] c = {1, 2, 3}; System.out.println(java.util.Collections.max(c)); A. The code is correct and displays 3. B. The code is correct and displays 3.0. C. The code has a compile error on Collections.max(c). c cannot be an array. D. The code has a compile error on Integer[] c = {1, 2, 3}

Analyze the following code: import java.util.Scanner; public class Test { public static void main(String[] args) { int sum = 0; for (int i = 0; i < 100000; i++) { Scanner input = new Scanner(System.in); sum += input.nextInt(); } } } A. The program does not compile because the Scanner input = new Scanner(System.in); statement is inside the loop. B. The program compiles, but does not run because the Scanner input = new Scanner(System.in); statement is inside the loop. C. The program compiles and runs, but it is not efficient and unnecessary to execute the Scanner input = new Scanner(System.in); statement inside the loop. You should move the statement before the loop. D. The program compiles, but does not run because there is not prompting message for entering the input

Analyze the following code: int i = 3434; double d = 3434; System.out.printf("%5.1f %5.1f", i, d); A. The code compiles and runs fine to display 3434.0 3434.0. B. The code compiles and runs fine to display 3434 3434.0. C. i is an integer, but the format specifier %5.1f specifies a format for double value. The code has an error.

Analyze the following code: public class Test { private int t; public static void main(String[] args) { int x; System.out.println(t); } } A. The variable t is not initialized and therefore causes errors. B. The variable t is private and therefore cannot be accessed in the main method. C. t is non-static and it cannot be referenced in a static context in the main method. D. The variable x is not initialized and therefore causes errors. E. The program compiles and runs fine

Analyze the following code: public class Test { public static void main(String[] args) { double[] x = {2.5, 3, 4}; for (double value: x) System.out.print(value + " "); } } A. The program displays 2.5, 3, 4 B. The program displays 2.5 3 4 C. The program displays 2.5 3.0 4.0 D. The program displays 2.5, 3.0 4.0 E. The program has a syntax error because value is undefined

Analyze the following code: public class Test { public static void main(String[] args) { int n = 10000 * 10000 * 10000; System.out.println("n is " + n); } } A. The program displays n is 1000000000000. B. The result of 10000 * 10000 * 10000 is too large to be stored in an int variable n. This causes an overflow and the program is aborted. C. The result of 10000 * 10000 * 10000 is too large to be stored in an int variable n. This causes an overflow and the program continues to execute because Java does not report errors on overflow. D. The result of 10000 * 10000 * 10000 is too large to be stored in an int variable n. This causes an underflow and the program is aborted. E. The result of 10000 * 10000 * 10000 is too large to be stored in an int variable n. This causes an underflow and the program continues to execute because Java does not report errors on underflow.

Analyze the following code: public class Test { public static void main(String[] args) { int[] a = new int[4]; a[1] = 1; a = new int[2]; System.out.println("a[1] is " + a[1]); } } A. The program has a compile error because new int[2] is assigned to a. B. The program has a runtime error because a[1] is not initialized. C. The program displays a[1] is 0. D. The program displays a[1] is 1

Analyze the following code: public class Test { public static void main(String[] args) { final int[] x = {1, 2, 3, 4}; int[] y = x; x = new int[2]; for (int i = 0; i < y.length; i++) System.out.print(y[i] + " "); } } A. The program displays 1 2 3 4 B. The program displays 0 0 C. The program has a compile error on the statement x = new int[2], because x is final and cannot be changed. D. The elements in the array x cannot be changed, because x is final

Analyze the following code: public class Test { public static void main(String[] args) { int[] x = new int[5]; int i; for (i = 0; i < x.length; i++) x[i] = i; System.out.println(x[i]); } } A. The program displays 0 1 2 3 4. B. The program displays 4. C. The program has a runtime error because the last statement in the main method causes ArrayIndexOutOfBoundsException. D. The program has a compile error because i is not defined in the last statement in the main method

Analyze the following code: public class Test1 { public static void main(String[] args) { xMethod(new double[]{3, 3}); xMethod(new double[5]); xMethod(new double[3]{1, 2, 3}); } public static void xMethod(double[] a) { System.out.println(a.length); } } A. The program has a compile error because xMethod(new double[]{3, 3}) is incorrect. B. The program has a compile error because xMethod(new double[5]) is incorrect. C. The program has a compile error because xMethod(new double[3]{1, 2, 3}) is incorrect. D. The program has a runtime error because a is null

Analyze the following fragment: double sum = 0; double d = 0; while (d != 10.0) { d += 0.1; sum += sum + d; } A. The program does not compile because sum and d are declared double, but assigned with integer value 0. B. The program never stops because d is always 0.1 inside the loop. C. The program may not stop because of the phenomenon referred to as numerical inaccuracy for operating with floating-point numbers. D. After the loop, sum is 0 + 0.1 + 0.2 + 0.3 + ... + 1.9

Analyze the following program fragment: int x; double d = 1.5; switch (d) { case 1.0: x = 1; case 1.5: x = 2; case 2.0: x = 3; } A. The program has a compile error because the required break statement is missing in the switch statement. B. The program has a compile error because the required default case is missing in the switch statement. C. The switch control variable cannot be double. D. No errors.

Assume Cylinder is a subtype of Circle. Analyze the following code: Cylinder cy = new Cylinder(1, 1); Circle c = cy; A. The code has a compile error. B. The code has a runtime error. C. The code is fine

Assume StringBuilder strBuf is "ABCDEFG", after invoking _________, strBuf contains "ABCRRRRDEFG". A. strBuf.insert(1, "RRRR") B. strBuf.insert(2, "RRRR") C. strBuf.insert(3, "RRRR") D. strBuf.insert(4, "RRRR")

Assume StringBuilder strBuf is "ABCDEFG", after invoking _________, strBuf contains "AEFG". A. strBuf.delete(0, 3) B. strBuf.delete(1, 3) C. strBuf.delete(1, 4) D. strBuf.delete(2, 4)

Assume int[] t = {1, 2, 3, 4}. What is t.length? A. 0 B. 3 C. 4 D. 5

Given the declaration Circle x = new Circle(), which of the following statement is most accurate. A. x contains an int value. B. x contains an object of the Circle type. C. x contains a reference to a Circle object. D. You can assign an int value to x

Given the declaration Circle[] x = new Circle[10], which of the following statement is most accurate? A. x contains an array of ten int values. B. x contains an array of ten objects of the Circle type. C. x contains a reference to an array and each element in the array can hold a reference to a Circle object. D. x contains a reference to an array and each element in the array can hold a Circle object

Given the following four patterns, Pattern A Pattern B Pattern C Pattern D 1 1 2 3 4 5 6 1 1 2 3 4 5 6 1 2 1 2 3 4 5 2 1 1 2 3 4 5 1 2 3 1 2 3 4 3 2 1 1 2 3 4 1 2 3 4 1 2 3 4 3 2 1 1 2 3 1 2 3 4 5 1 2 5 4 3 2 1 1 2 1 2 3 4 5 6 1 6 5 4 3 2 1 1 Which of the pattern is produced by the following code? for (int i = 1; i <= 6; i++) { for (int j = 6; j >= 1; j--) System.out.print(j <= i ? j + " " : " " + " "); System.out.println(); } A. Pattern A B. Pattern B C. Pattern C D. Pattern D

Given the following method static void nPrint(String message, int n) { while (n > 0) { System.out.print(message); n--; } } What is k after invoking nPrint("A message", k)? int k = 2; nPrint("A message", k); A. 0 B. 1 C. 2 D. 3

Given the following program: public class Test { public static void main(String[] args) { for (int i = 0; i < args.length; i++) { System.out.print(args[i] + " "); } } } What is the output, if you run the program using java Test 1 2 3 A. 3 B. 1 C. 1 2 3 D. 1 2

Given two reference variables t1 and t2, if t1.equals(t2) is true, t1 == t2 ___________. A. is always true B. is always false C. may be true or false

Given |x - 2| <= 4, which of the following is true? A. x - 2 <= 4 && x - 2 >= 4 B. x - 2 <= 4 && x - 2 > -4 C. x - 2 <= 4 && x - 2 >= -4 D. x - 2 <= 4 || x - 2 >= -4

How can you get the word "abc" in the main method from the following call? java Test "+" 3 "abc" 2 A. args[0] B. args[1] C. args[2] D. args[3]

The main method header is written as: A. public static void main(string[ ] args) B. public static void Main(String[ ] args) C. public static void main(String[ ] args) D. public static main(String[ ] args) E. public void main(String[ ] args)

The order of the precedence (from high to low) of the operators binary +, *, &&, ||, ^ is: A. &&, ||, ^, *, + B. *, +, &&, ||, ^ C. *, +, ^, &&, || D. *, +, ^, ||, && E. ^, ||, &&, *, +

The output from the following code is __________. java.util.ArrayList<String> list = new java.util.ArrayList<String>(); list.add("New York"); java.util.ArrayList<String> list1 = list; list.add("Atlanta"); list1.add("Dallas"); System.out.println(list1); A. [New York] B. [New York, Atlanta] C. [New York, Atlanta, Dallas] D. [New York, Dallas]

The relationship between an interface and the class that implements it is A. Composition B. Aggregation C. Inheritance D. None

The statement System.out.printf("%5d", 123456) outputs ___________. A. 12345 B. 23456 C. 123456 D. 12345.6

To create an InputStream to read from a file on a Web server, you use the method __________ in the URL class. A. getInputStream(); B. obtainInputStream(); C. openStream(); D. connectStream();

To divide BigDecimal b1 by b2 and assign the result to b1, you write _________. A. b1.divide(b2); B. b2.divide(b1); C. b1 = b1.divide(b2); D. b1 = b2.divide(b1); E. b2 = b2.divide(b1);

To obtain the current second, use _________. A. System.currentTimeMillis() % 3600 B. System.currentTimeMillis() % 60 C. System.currentTimeMillis() / 1000 % 60 D. System.currentTimeMillis() / 1000 / 60 % 60 E. System.currentTimeMillis() / 1000 / 60 / 60 % 24

To place a node in the left of a BorderPane p, use ___________. A. p.setEast(node); B. p.placeLeft(node); C. p.setLeft(node); D. p.left(node);

To prevent a class from being instantiated, _____________________ A. don't use any modifiers on the constructor. B. use the public modifier on the constructor. C. use the private modifier on the constructor. D. use the static modifier on the constructor.

What exception type does the following program throw? public class Test { public static void main(String[] args) { String s = "abc"; System.out.println(s.charAt(3)); } } A. ArithmeticException B. ArrayIndexOutOfBoundsException C. StringIndexOutOfBoundsException D. ClassCastException E. No exception

What is displayed by the following code? System.out.print("A,B;C".replaceAll(",;", "#") + " "); System.out.println("A,B;C".replaceAll("[,;]", "#")); A. A B C A#B#C B. A#B#C A#B#C C. A,B;C A#B#C D. A B C A B C

What is displayed by the following code? public static void main(String[] args) { String[] tokens = "Welcome to Java".split("o"); for (int i = 0; i < tokens.length; i++) { System.out.print(tokens[i] + " "); } } A. Welcome to Java B. Welc me to Java C. Welc me t Java D. Welcome t Java

What is displayed by the following statement? System.out.println("Java is neat".replaceAll("is", "AAA")); A. JavaAAAneat B. JavaAAA neat C. Java AAA neat D. Java AAAneat

What is displayed on the console when running the following program? public class Test { public static void main(String[] args) { try { System.out.println("Welcome to Java"); int i = 0; double y = 2.0 / i; System.out.println("Welcome to HTML"); } finally { System.out.println("The finally clause is executed"); } } } A. Welcome to Java. B. Welcome to Java followed by The finally clause is executed in the next line. C. The program displays three lines: Welcome to Java, Welcome to HTML, The finally clause is executed. D. None of the above.

What is displayed on the console when running the following program? public class Test { public static void main(String[] args) { try { System.out.println("Welcome to Java"); int i = 0; int y = 2/i; System.out.println("Welcome to Java"); } catch (RuntimeException ex) { System.out.println("Welcome to Java"); } finally { System.out.println("End of the block"); } System.out.println("End of the block"); } } A. The program displays Welcome to Java three times followed by End of the block. B. The program displays Welcome to Java two times followed by End of the block. C. The program displays Welcome to Java two times followed by End of the block two times. D. You cannot catch RuntimeException errors

What is displayed on the console when running the following program? public class Test { public static void main(String[] args) { try { method(); System.out.println("After the method call"); } catch (RuntimeException ex) { System.out.println("RuntimeException"); } catch (Exception ex) { System.out.println("Exception"); } } static void method() throws Exception { try { String s = "5.6"; Integer.parseInt(s); // Cause a NumberFormatException int i = 0; int y = 2 / i; System.out.println("Welcome to Java"); } catch (NumberFormatException ex) { System.out.println("NumberFormatException"); throw ex; } catch (RuntimeException ex) { System.out.println("RuntimeException"); } } } A. The program displays NumberFormatException twice. B. The program displays NumberFormatException followed by After the method call. C. The program displays NumberFormatException followed by RuntimeException. D. The program has a compile error

What is displayed on the console when running the following program? public class Test { public static void main(String[] args) { try { method(); System.out.println("After the method call"); } catch (RuntimeException ex) { System.out.println("RuntimeException"); } catch (Exception ex) { System.out.println("Exception"); } } static void method() throws Exception { try { String s = "5.6"; Integer.parseInt(s); // Cause a NumberFormatException int i = 0; int y = 2 / i; System.out.println("Welcome to Java"); } catch (RuntimeException ex) { System.out.println("RuntimeException"); } catch (Exception ex) { System.out.println("Exception"); } } } A. The program displays RuntimeException twice. B. The program displays Exception twice. C. The program displays RuntimeException followed by After the method call. D. The program displays Exception followed by RuntimeException. E. The program has a compile error

What is i printed in the following code? public class Test { public static void main(String[] args) { int j = 0; int i = j++ + j * 5; System.out.println("What is i? " + i); } } A. 0 B. 1 C. 5 D. 6

What is the best suitable relationship between Employee and Faculty? A. Composition B. Aggregation C. Inheritance D. None

What is the number of iterations in the following loop? for (int i = 1; i < n; i++) { // iteration } A. 2*n B. n C. n - 1 D. n + 1

What is the output for the second statement in the main method? public class Foo { static int i = 0; static int j = 0; public static void main(String[] args) { int i = 2; int k = 3; { int j = 3; System.out.println("i + j is " + i + j); } k = i + j; System.out.println("k is " + k); System.out.println("j is " + j); } } A. k is 0 B. k is 1 C. k is 2 D. k is 3

What is the output of the following code: public class Test { public static void main(String[] args) { String s1 = new String("Java"); String s2 = new String("Java"); System.out.print((s1 == s2) + " " + (s1.equals(s2))); } } A. false false B. true true C. false true D. true false

What is the output of the following code? ArrayList<java.util.Date> list = new ArrayList<java.util.Date>(); java.util.Date d = new java.util.Date(); list.add(d); list.add(d); System.out.println((list.get(0) == list.get(1)) + " " + (list.get(0)).equals(list.get(1))); A. true false B. false true C. true true D. false false

What is the output of the following code? public class Test { public static void main(String[] args) { int[][][] data = {{{1, 2}, {3, 4}}, {{5, 6}, {7, 8}}}; System.out.print(ttt(data[0])); } public static int ttt(int[][] m) { int v = m[0][0]; for (int i = 0; i < m.length; i++) for (int j = 0; j < m[i].length; j++) if (v < m[i][j]) v = m[i][j]; return v; } } A. 1 B. 2 C. 4 D. 5 E. 6

What is the output of the following code? public class Test { public static void main(String[] args) { String s1 = new String("Welcome to Java!"); String s2 = s1.toUpperCase(); if (s1 == s2) System.out.println("s1 and s2 reference to the same String object"); else if (s1.equals(s2)) System.out.println("s1 and s2 have the same contents"); else System.out.println("s1 and s2 have different contents"); } } A. s1 and s2 reference to the same String object B. s1 and s2 have the same contents C. s1 and s2 have different contents

What is the output of the third println statement in the main method? public class Foo { int i; static int s; public static void main(String[] args) { Foo f1 = new Foo(); System.out.println("f1.i is " + f1.i + " f1.s is " + f1.s); Foo f2 = new Foo(); System.out.println("f2.i is " + f2.i + " f2.s is " + f2.s); Foo f3 = new Foo(); System.out.println("f3.i is " + f3.i + " f3.s is " + f3.s); } public Foo() { i++; s++; } } A. f3.i is 1 f3.s is 1 B. f3.i is 1 f3.s is 2 C. f3.i is 1 f3.s is 3 D. f3.i is 3 f3.s is 1 E. f3.i is 3 f3.s is 3

What is the value of balance after the following code is executed? int balance = 10; while (balance >= 1) { if (balance < 9) break; balance = balance - 9; } A. -1 B. 0 C. 1 D. 2

Which class do you use to read data from a text file? A. File B. PrintWriter C. Scanner D. System

Which is the advantage of encapsulation? A. Only public methods are needed. B. Making the class final causes no consequential changes to other code. C. It changes the implementation without changing a class's contract and causes no consequential changes to other code. D. It changes a class's contract without changing the implementation and causes no consequential changes to other code.

Which method can be used to create an input object for file temp.txt? A. new Scanner("temp.txt") B. new Scanner(temp.txt) C. new Scanner(new File("temp.txt")) D. new Scanner(File("temp.txt"))

Which of the following classes cannot be extended? A. class A { } B. class A { private A() { }} C. final class A { } D. class A { protected A() { }}

Which of the following is incorrect? A. int x = 9; B. long x = 9; C. float x = 1.0; D. double x = 1.0;

Given the following code, find the compile error. public class Test { public static void main(String[] args) { m(new GraduateStudent()); m(new Student()); m(new Person()); m(new Object()); } public static void m(Student x) { System.out.println(x.toString()); } } class GraduateStudent extends Student { } class Student extends Person { @Override public String toString() { return "Student"; } } class Person extends Object { @Override public String toString() { return "Person"; } } A. m(new GraduateStudent()) causes an error B. m(new Student()) causes an error C. m(new Person()) causes an error D. m(new Object()) causes an error

C and D

How can you initialize an array of two characters to 'a' and 'b'? A. char[] charArray = new char[2]; charArray = {'a', 'b'}; B. char[2] charArray = {'a', 'b'}; C. char[] charArray = {'a', 'b'}; D. char[] charArray = new char[]{'a', 'b'};

C and D

Programming style is important, because ______________. A. a program may not compile if it has a bad style B. good programming style can make a program run faster C. good programming style makes a program more readable D. good programming style helps reduce programming errors

C and D

To add BigInteger b1 to b2, you write _________. A. b1.add(b2); B. b2.add(b1); C. b2 = b1.add(b2); D. b2 = b2.add(b1); E. b1 = b2.add(b1);

C and D

To add a circle object into a pane, use _________. A. pane.add(circle); B. pane.addAll(circle); C. pane.getChildren().add(circle); D. pane.getChildren().addAll(circle);

C and D

To add a node into a pane, use ______. A. pane.add(node); B. pane.addAll(node); C. pane.getChildren().add(node); D. pane.getChildren().addAll(node);

C and D

To remove a node from the pane, use ______. A. pane.remove(node); B. pane.removeAll(node); C. pane.getChildren().remove(node); D. pane.getChildren().removeAll(node);

C and D

Which of the following are binding properties? A. Integer B. Double C. IntegerProperty D. DoubleProperty E. String

C and D

Which of the following assignment statements is incorrect? A. i = j = k = 1; B. i = 1; j = 1; k = 1; C. i = 1 = j = 1 = k = 1; D. i == j == k == 1;

C and D

Which of the following can be used as a source for a binding properties? A. Integer B. Double C. IntegerProperty D. DoubleProperty E. String

C and D

Which of the following statements correctly rotates the button 45 degrees counterclockwise? A. button.setRotate(45); B. button.setRotate(Math.toRadians(45)); C. button.setRotate(360 - 45); D. button.setRotate(-45);

C and D

Assume s is "ABCABC", the method __________ returns a new string "aBCaBC". A. s.toLowerCase(s) B. s.toLowerCase() C. s.replace('A', 'a') D. s.replace('a', 'A') E. s.replace("ABCABC", "aBCaBC")

C and E

The Rational class in this chapter is defined as a subclass of java.lang.Number. Which of the following expressions is correct? A. Rational.doubleValue(); B. Rational.doubleValue("5/4"); C. new Rational(5, 4).doubleValue(); D. new Rational(5, 4).toDoubleValue(); E. new Rational(5, 4).intValue();

C and E

Which of the following is not a correct method in the Character class? A. isLetterOrDigit(char) B. isLetter(char) C. isDigit() D. toLowerCase(char) E. toUpperCase()

C and E

Which of the following lines is not a Java comment? A. /** comments */ B. // comments C. -- comments D. /* comments */ E. ** comments **

C and E

________ is the brain of the computer

CPU

"AbA".compareToIgnoreCase("abC") returns ___________. A. 1 B. 2 C. -1 D. -2 E. 0

A variable defined inside a method is referred to as __________. A. a global variable B. a method variable C. a block variable D. a local variable

Analyze the following code. Number[] numberArray = new Integer[2]; numberArray[0] = new Double(1.5); Which of the following statements is correct? A. You cannot use Number as a data type since it is an abstract class. B. Since each element of numberArray is of the Number type, you cannot assign an Integer object to it. C. Since each element of numberArray is of the Number type, you cannot assign a Double object to it. D. At runtime, new Integer[2] is assigned to numberArray. This makes each element of numberArray an Integer object. So you cannot assign a Double object to it

Analyze the following code. 1. public class Test { 2. public static void main(String[] args) { 3. Fruit[] fruits = {new Fruit(2), new Fruit(3), new Fruit(1)}; 4. java.util.Arrays.sort(fruits); 5. } 6. } class Fruit { private double weight; public Fruit(double weight) { this.weight = weight; } } A. The program has a compile error because the Fruit class does not have a no-arg constructor. B. The program has a runtime error on Line 3 because the Fruit class does not have a no-arg constructor. C. The program has a compile error on Line 4 because the Fruit class does not implement the java.lang.Comparable interface and the Fruit objects are not comparable. D. The program has a runtime error on Line 4 because the Fruit class does not implement the java.lang.Comparable interface and the Fruit objects are not comparable

Analyze the following code. I: public class Test { public static void main(String[] args) { System.out.println("Welcome to Java!"); } } II: public class Test { public static void main(String[] args) { System.out.println("Welcome to Java!"); } } A. Both I and II can compile and run and display Welcome to Java, but the code in II has a better style than I. B. Only the code in I can compile and run and display Welcome to Java. C. Only the code in II can compile and run and display Welcome to Java. D. Both I and II can compile and run and display Welcome to Java, but the code in I has a better style than II.

Analyze the following code. double sum = 0; for (double d = 0; d < 10; sum += sum + d) { d += 0.1; } A. The program has a syntax error because the adjustment statement is incorrect in the for loop. B. The program has a syntax error because the control variable in the for loop cannot be of the double type. C. The program compiles but does not stop because d would always be less than 10. D. The program compiles and runs fine.

Analyze the following code. public class Test { int x; public Test(String t) { System.out.println("Test"); } public static void main(String[] args) { Test test = new Test(); System.out.println(test.x); } } A. The program has a compile error because System.out.println method cannot be invoked from the constructor. B. The program has a compile error because x has not been initialized. C. The program has a compile error because you cannot create an object from the class that defines the object. D. The program has a compile error because Test does not have a default constructor

Analyze the following code. public class Test { public static void main(String[] args) { int month = 09; System.out.println("month is " + month); } } A. The program displays month is 09. B. The program displays month is 9. C. The program displays month is 9.0. D. The program has a syntax error, because 09 is an incorrect literal value

Analyze the following code. public class Test { public static void main(String[] args) { java.util.Date x = new java.util.Date(); java.util.Date y = x.clone(); System.out.println(x = y); } } A. A java.util.Date object is not cloneable. B. x = y in System.out.println(x = y) causes a compile error because you cannot have an assignment statement inside a statement. C. x = y in System.out.println(x = y) causes a runtime error because you cannot have an assignment statement inside a statement. D. The program has a compile error because the return type of the clone() method is java.lang.Object

Analyze the following code. Which of the following statements is correct? public class Test { public static void main(String[] args) { Number x = new Integer(3); System.out.println(x.intValue()); System.out.println((Integer)x.compareTo(new Integer(4))); } } A. The program has a compile error because an Integer instance cannot be assigned to a Number variable. B. The program has a compile error because intValue is an abstract method in Number. C. The program has a compile error because x cannot be cast into Integer. D. The program has a compile error because the member access operator (.) is executed before the casting operator. E. The program compiles and runs fine

To assign a double variable d to a float variable x, you write A. x = (long)d B. x = (int)d; C. x = d; D. x = (float)d;

Analyze the following code: double[] array = {1, 2, 3}; ArrayList<Double> list = new ArrayList<>(Arrays.asList(array)); System.out.println(list); A. The code is correct and displays [1, 2, 3]. B. The code is correct and displays [1.0, 2.0, 3.0]. C. The code has a compile error because an integer such as 1 is automatically converted into an Integer object, but the array element type is Double. D. The code has a compile error because asList(array) requires that the array elements are objects

Analyze the following code: Code 1: int number = 45; boolean even; if (number % 2 == 0) even = true; else even = false; Code 2: int number = 45; boolean even = (number % 2 == 0); A. Code 1 has compile errors. B. Code 2 has compile errors. C. Both Code 1 and Code 2 have compile errors. D. Both Code 1 and Code 2 are correct, but Code 2 is better

Analyze the following code: boolean even = false; if (even = true) { System.out.println("It is even"); } A. The program has a compile error. B. The program has a runtime error. C. The program runs fine, but displays nothing. D. The program runs fine and displays It is even.

Analyze the following code: public class Test { public static void main(String[] args) { String s = new String("Welcome to Java"); Object o = s; String d = (String)o; } } A. When assigning s to o in Object o = s, a new object is created. B. When casting o to s in String d = (String)o, a new object is created. C. When casting o to s in String d = (String)o, the contents of o is changed. D. s, o, and d reference the same String object

Analyze the following code: public class Test { public static void main(String[] args) { new B(); } } class A { int i = 7; public A() { setI(20); System.out.println("i from A is " + i); } public void setI(int i) { this.i = 2 * i; } } class B extends A { public B() { // System.out.println("i from B is " + i); } @Override public void setI(int i) { this.i = 3 * i; } } A. The constructor of class A is not called. B. The constructor of class A is called and it displays "i from A is 7". C. The constructor of class A is called and it displays "i from A is 40". D. The constructor of class A is called and it displays "i from A is 60".

Analyze the following code: public class Test { public static void main(String[] args) { try { String s = "5.6"; Integer.parseInt(s); // Cause a NumberFormatException int i = 0; int y = 2 / i; } catch (Exception ex) { System.out.println("NumberFormatException"); } catch (RuntimeException ex) { System.out.println("RuntimeException"); } } } A. The program displays NumberFormatException. B. The program displays RuntimeException. C. The program displays NumberFormatException followed by RuntimeException. D. The program has a compile error

Analyze the following code: public class Test { public static void main(String[] args) { B b = new B(); b.m(5); System.out.println("i is " + b.i); } } class A { int i; public void m(int i) { this.i = i; } } class B extends A { public void m(String s) { } } A. The program has a compile error, because m is overridden with a different signature in B. B. The program has a compile error, because b.m(5) cannot be invoked since the method m(int) is hidden in B. C. The program has a runtime error on b.i, because i is not accessible from b. D. The method m is not overridden in B. B inherits the method m from A and defines an overloaded method m in B

Assume Calendar calendar = new GregorianCalendar(). __________ returns the week of the year. A. calendar.get(Calendar.MONTH) B. calendar.get(Calendar.MONTH_OF_YEAR) C. calendar.get(Calendar.WEEK_OF_MONTH) D. calendar.get(Calendar.WEEK_OF_YEAR)

Assume an employee can work for only one company. What is the best suitable relationship between Company and Employee? A. None B. Aggregation C. Inheritance D. Composition

Assume int[] scores = {1, 20, 30, 40, 50}, what value does java.util.Arrays.binarySearch(scores, 30) return? A. 0 B. -1 C. 1 D. 2 E. -2

Assume s is " abc ", the method __________ returns a new string "abc". A. s.trim(s) B. trim(s) C. String.trim(s) D. s.trim()

Assume x = 4, which of the following is true? A. !(x == 4) B. x != 4 C. x == 5 D. x != 5

Composition means ______________. A. that data fields should be declared private B. that a class extends another class C. that a variable of supertype refers to a subtype object D. that a class contains a data field that references another object

Consider the following incomplete code: public class Test { public static void main(String[] args) { System.out.println(f(5)); } public static int f(int number) { // Missing body } } The missing method body should be ________. A. return "number"; B. System.out.println(number); C. System.out.println("number"); D. return number;

For the binarySearch method in Section 7.10.2, what is low and high after the first iteration of the while loop when invoking binarySearch(new int[]{1, 4, 6, 8, 10, 15, 20}, 11)? A. low is 0 and high is 6 B. low is 5 and high is 5 C. low is 3 and high is 6 D. low is 5 and high is 4 E. low is 6 and high is 5

Given the following code: class C1 {} class C2 extends C1 { } class C3 extends C2 { } class C4 extends C1 {} C1 c1 = new C1(); C2 c2 = new C2(); C3 c3 = new C3(); C4 c4 = new C4(); Which of the following expressions evaluates to false? A. c1 instanceof C1 B. c2 instanceof C1 C. c3 instanceof C1 D. c4 instanceof C2

Given the following method static void nPrint(String message, int n) { while (n > 0) { System.out.print(message); n--; } } What is the output of the call nPrint('a', 4)? A. aaaaa B. aaaa C. aaa D. invalid call

How many times is the println statement executed? for (int i = 0; i < 10; i++) for (int j = 0; j < i; j++) System.out.println(i * j) A. 100 B. 20 C. 10 D. 45

Identify the problems in the following code. public class Test { public static void main(String argv[]) { System.out.println("argv.length is " + argv.length); } } A. The program has a compile error because String argv[] is wrong and it should be replaced by String[] args. B. The program has a compile error because String args[] is wrong and it should be replaced by String args[]. C. If you run this program without passing any arguments, the program would have a runtime error because argv is null. D. If you run this program without passing any arguments, the program would display argv.length is 0.

Invoking _________ returns the number of the elements in an ArrayList x. A. x.getSize() B. x.getLength(0) C. x.length(1) D. x.size()

Show the output of running the class Test in the following code lines: interface A { } class C { } class B extends D implements A { } public class Test { public static void main(String[] args) { B b = new B(); if (b instanceof A) System.out.println("b is an instance of A"); if (b instanceof C) System.out.println("b is an instance of C"); } } class D extends C { } A. Nothing. B. b is an instance of A. C. b is an instance of C. D. b is an instance of A followed by b is an instance of C

Show the output of the following code: public class Test { public static void main(String[] args) { int[] x = {1, 2, 3, 4, 5}; increase(x); int[] y = {1, 2, 3, 4, 5}; increase(y[0]); System.out.println(x[0] + " " + y[0]); } public static void increase(int[] x) { for (int i = 0; i < x.length; i++) x[i]++; } public static void increase(int y) { y++; } } A. 0 0 B. 1 1 C. 2 2 D. 2 1 E. 1 2

Suppose a method p has the following heading: public static int[] p() What return statement may be used in p()? A. return 1; B. return {1, 2, 3}; C. return int[]{1, 2, 3}; D. return new int[]{1, 2, 3};

Suppose the input for number is 9. What is the output from running the following program? import java.util.Scanner; public class Test { public static void main(String[] args) { Scanner input = new Scanner(System.in); System.out.print("Enter an integer: "); int number = input.nextInt(); int i; boolean isPrime = true; for (i = 2; i < number && isPrime; i++) { if (number % i == 0) { isPrime = false; } } System.out.println("i is " + i); if (isPrime) System.out.println(number + " is prime"); else System.out.println(number + " is not prime"); } } A. i is 3 followed by 9 is prime B. i is 3 followed by 9 is not prime C. i is 4 followed by 9 is prime D. i is 4 followed by 9 is not prime

Suppose you enter 34.3 57.8 789, then press the ENTER key. Analyze the following code. Scanner input = new Scanner(System.in); double v1 = input.nextDouble(); double v2 = input.nextDouble(); String line = input.nextLine(); A. After the last statement is executed, line contains characters '7', '8', '9'. B. After the last statement is executed, line contains characters '7', '8', '9', '\n'. C. After the last statement is executed, line contains characters ' ', '7', '8', '9', '\n'. D. After the last statement is executed, line contains characters ' ', '7', '8', '9'

The Rational class in this chapter extends java.lang.Number and implements java.lang.Comparable. Analyze the following code. 1. public class Test { 2. public static void main(String[] args) { 3. Number[] numbers = {new Rational(1, 2), new Integer(4), new Double(5.6)}; 4. java.util.Arrays.sort(numbers); 5. } 6. } A. The program has a compile error because numbers is declared as Number[], so you cannot assign {new Rational(1, 2), new Integer(4), new Double(5.6)} to it. B. The program has a runtime error because numbers is declared as Number[], so you cannot assign {new Rational(1, 2), new Integer(4), new Double(5.6)} to it. C. The program has a compile error because numbers is declared as Number[], so you cannot pass it to Arrays.sort(Object[]). D. The program has a runtime error because the compareTo methods in Rational, Integer, and Double classes do not compare the value of one type with a value of another type

The Unicode of 'a' is 97. What is the Unicode for 'c'? A. 96 B. 97 C. 98 D. 99

The __________ method copies the sourceArray to the targetArray. A. System.copyArrays(sourceArray, 0, targetArray, 0, sourceArray.length); B. System.copyarrays(sourceArray, 0, targetArray, 0, sourceArray.length); C. System.arrayCopy(sourceArray, 0, targetArray, 0, sourceArray.length); D. System.arraycopy(sourceArray, 0, targetArray, 0, sourceArray.length);

The __________ method parses a string s to a double value. A. double.parseDouble(s); B. Double.parsedouble(s); C. double.parse(s); D. Double.parseDouble(s);

The following loop displays _______________. for (int i = 1; i <= 10; i++) { System.out.print(i + " "); i++; } The correct answer is D. A. 1 2 3 4 5 6 7 8 9 B. 1 2 3 4 5 6 7 8 9 10 C. 1 2 3 4 5 D. 1 3 5 7 9 E. 2 4 6 8 10

The output from the following code is __________. java.util.ArrayList<String> list = new java.util.ArrayList<String>(); list.add("New York"); java.util.ArrayList<String> list1 = (java.util.ArrayList<String>)(list.clone()); list.add("Atlanta"); list1.add("Dallas"); System.out.println(list1); A. [New York] B. [New York, Atlanta] C. [New York, Atlanta, Dallas] D. [New York, Dallas]

The statement System.out.printf("%10s", 123456) outputs ___________. (Note: * represents a space) A. 123456**** B. 23456***** C. 12345***** D. ****123456

The statement System.out.printf("%3.1e", 1234.56) outputs ___________. A. 0.1e+04 B. 0.123456e+04 C. 0.123e+04 D. 1.2e+03 E. 1.23+03

To add two nodes node1 and node2 into a pane, use ______. A. pane.add(node1, node2); B. pane.addAll(node1, node2); C. pane.getChildren().add(node1, node2); D. pane.getChildren().addAll(node1, node2);

Analyze the following code. public class Test { int x; public Test(String t) { System.out.println("Test"); } public static void main(String[] args) { Test test = null; System.out.println(test.x); } } A. The program has a compile error because test is not initialized. B. The program has a compile error because x has not been initialized. C. The program has a compile error because you cannot create an object from the class that defines the object. D. The program has a compile error because Test does not have a default constructor. E. The program has a runtime NullPointerException because test is null while executing test.x.

Assume Calendar calendar = new GregorianCalendar(). __________ returns the number of days in a month. A. calendar.get(Calendar.MONTH) B. calendar.get(Calendar.MONTH_OF_YEAR) C. calendar.get(Calendar.WEEK_OF_MONTH) D. calendar.get(Calendar.WEEK_OF_YEAR) E. calendar.getActualMaximum(Calendar.DAY_OF_MONTH)

Assume StringBuilder strBuf is "ABCCEFC", after invoking _________, strBuf contains "ABTTEFT". A. strBuf.replace('C', 'T') B. strBuf.replace("C", "T") C. strBuf.replace("CC", "TT") D. strBuf.replace('C', "TT") E. strBuf.replace(2, 7, "TTEFT")

Assume int[] scores = {1, 20, 30, 40, 50}, what value does java.util.Arrays.binarySearch(scores, 3) return? A. 0 B. -1 C. 1 D. 2 E. -2

Invoking _________ removes all elements in an ArrayList x. A. x.remove() B. x.clean() C. x.delete() D. x.empty() E. x.clear()

Suppose a method p has the following heading: public static int[][] p() What return statement may be used in p()? A. return 1; B. return {1, 2, 3}; C. return int[]{1, 2, 3}; D. return new int[]{1, 2, 3}; E. return new int[][]{{1, 2, 3}, {2, 4, 5}};

The System.currentTimeMillis() returns ________________ . A. the current time. B. the current time in milliseconds. C. the current time in milliseconds since midnight. D. the current time in milliseconds since midnight, January 1, 1970. E. the current time in milliseconds since midnight, January 1, 1970 GMT (the Unix time).

The statement System.out.printf("%3.1f", 1234.56) outputs ___________. A. 123.4 B. 123.5 C. 1234.5 D. 1234.56 E. 1234.6

To add a node to the the first row and second column in a GridPane pane, use ________. A. pane.getChildren().add(node, 1, 2); B. pane.add(node, 1, 2); C. pane.getChildren().add(node, 0, 1); D. pane.add(node, 0, 1); E. pane.add(node, 1, 0);

What is the output of the following code? int x = 0; while (x < 4) { x = x + 1; } System.out.println("x is " + x); A. x is 0 B. x is 1 C. x is 2 D. x is 3 E. x is 4

What is the output of the following program? public class Test { public static void main(String[] args) { int[][] values = {{3, 4, 5, 1}, {33, 6, 1, 2}}; int v = values[0][0]; for (int row = 0; row < values.length; row++) for (int column = 0; column < values[row].length; column++) if (v < values[row][column]) v = values[row][column]; System.out.print(v); } } A. 1 B. 3 C. 5 D. 6 E. 33

What is the value of times displayed? public class Test { public static void main(String[] args) { Count myCount = new Count(); int times = 0; for (int i=0; i<100; i++) increment(myCount, times); System.out.println( "myCount.count = " + myCount.count); System.out.println("times = "+ times); } public static void increment(Count c, int times) { c.count++; times++; } } class Count { int count; Count(int c) { count = c; } Count() { count = 1; } } A. 101 B. 100 C. 99 D. 98 E. 0

What would be the result of attempting to compile and run the following code? public class Test { public static void main(String[] args) { double[] x = new double[]{1, 2, 3}; System.out.println("Value is " + x[1]); } } A. The program has a compile error because the syntax new double[]{1, 2, 3} is wrong and it should be replaced by {1, 2, 3}. B. The program has a compile error because the syntax new double[]{1, 2, 3} is wrong and it should be replaced by new double[3]{1, 2, 3}; C. The program has a compile error because the syntax new double[]{1, 2, 3} is wrong and it should be replaced by new double[]{1.0, 2.0, 3.0}; D. The program compiles and runs fine and the output "Value is 1.0" is printed. E. The program compiles and runs fine and the output "Value is 2.0" is printed

Which of the following loops correctly computes 1/2 + 2/3 + 3/4 + ... + 99/100? A: double sum = 0; for (int i = 1; i <= 99; i++) { sum = i / (i + 1); } System.out.println("Sum is " + sum); B: double sum = 0; for (int i = 1; i < 99; i++) { sum += i / (i + 1); } System.out.println("Sum is " + sum); C: double sum = 0; for (int i = 1; i <= 99; i++) { sum += 1.0 * i / (i + 1); } System.out.println("Sum is " + sum); D: double sum = 0; for (int i = 1; i <= 99; i++) { sum += i / (i + 1.0); } System.out.println("Sum is " + sum); E: double sum = 0; for (int i = 1; i < 99; i++) { sum += i / (i + 1.0); } System.out.println("Sum is " + sum); A. BCD B. ABCD C. B D. CDE E. CD

Which of the following loops prints "Welcome to Java" 10 times? A: for (int count = 1; count <= 10; count++) { System.out.println("Welcome to Java"); } B: for (int count = 0; count < 10; count++) { System.out.println("Welcome to Java"); } C: for (int count = 1; count < 10; count++) { System.out.println("Welcome to Java"); } D: for (int count = 0; count <= 10; count++) { System.out.println("Welcome to Java"); } A. BD B. ABC C. AC D. BC E. AB

Which of the following operators are right-associative. A. * B. + (binary +) C. % D. && E. =

Which of the following statements are true? A. If a file (e.g., c:\temp.txt) does not exist, new File("c:\\temp.txt") returns null. B. If a directory (e.g., c:\liang) does not exist, new File("c:\liang") returns null. C. If a file (e.g., c:\temp.txt) does not exist, new File("c:\\temp.txt") creates a new file named c:\temp.txt. D. If a directory (e.g., c:\liang) does not exist, new File("c:\liang") creates a new directory named c:\liang. E. None of the above

You should fill in the blank in the following code with ______________. public class Test { public static void main(String[] args) { System.out.print("The grade is "); printGrade(78.5); System.out.print("The grade is "); printGrade(59.5); } public static __________ printGrade(double score) { if (score >= 90.0) { System.out.println('A'); } else if (score >= 80.0) { System.out.println('B'); } else if (score >= 70.0) { System.out.println('C'); } else if (score >= 60.0) { System.out.println('D'); } else { System.out.println('F'); } } } A. int B. double C. boolean D. char E. void

________ is the physical aspect of the computer that can be seen.

Hardware

Which of the following code has the best style? I: public class Test { public static void main(String[] args) { System.out.println("Welcome to Java!"); } } II: public class Test { public static void main(String[] args) { System.out.println("Welcome to Java!"); } } III: public class Test { public static void main(String[] args) { System.out.println("Welcome to Java!"); } } IV: public class Test { public static void main(String[] args) { System.out.println("Welcome to Java!"); } }

________ contains predefined classes and interfaces for developing Java programs

Java API

_______ provides an integrated development environment (IDE) for rapidly developing Java programs. Editing, compiling, building, debugging, and online help are integrated in one graphical user interface

Java IDE

_______ consists of a set of separate programs for developing and testing Java programs, each of which is invoked from a command line

Java JDK

Java compiler translates Java source code into ________

Java bytecode

________ is a technical definition of the language that includes the syntax and semantics of the Java programming language

Java language specification

_________ is a software that interprets Java bytecode

Java virtual machine

How do you write 2.5 ^ 3.1 in Java?

Math.pow(2.5, 3.1)

The __________ method returns a raised to the power of b

Math.pow(a, b)

_____________ is a formal process that seeks to understand the problem and document in detail what the software system needs to do

Requirements specification

Given two reference variables t1 and t2, if t1 == t2 is true, t1.equals(t2) must be ___________. A. true B. false

In Java, the word true is _______

a Boolean literal

If you forget to put a closing quotation mark on a string, what kind of error will be raised?

a compile error

If a program compiles fine, but it produces incorrect result, then the program suffers _________

a logic error

Due to security reasons, Java ___________ cannot run from a Web browser in the new version of Java

applets

What is the exact output of the following code? double area = 3.5; System.out.print("area"); System.out.print(area);

area3.5

An instance of _________ are unchecked exceptions. A. RuntimeException B. Exception C. Error D. Throwable E. NumberFormatException

A, C and E

If you enter 1 2 3, when you run this program, what will be the output? import java.util.Scanner; public class Test1 { public static void main(String[] args) { Scanner input = new Scanner(System.in); System.out.print("Enter three numbers: "); double number1 = input.nextDouble(); double number2 = input.nextDouble(); double number3 = input.nextDouble(); // Compute average double average = (number1 + number2 + number3) / 3; // Display result System.out.println(average); } }

2.0

Which of the following is incorrect? A. A constructor may be static. B. A constructor may be private. C. A constructor may invoke a static method. D. A constructor may invoke an overloaded constructor. E. A constructor invokes its superclass no-arg constructor by default if a constructor does not invoke an overloaded constructor or its superclass?s constructor.

Which of the following statements are true? A. A Node can be placed in a Pane. B. A Node can be placed in a Scene. C. A Pane can be placed in a Control. D. A Shape can be placed in a Control.

Which of the following statements regarding abstract methods is false? A. An abstract class can have instances created using the constructor of the abstract class. B. An abstract class can be extended. C. A subclass of a non-abstract superclass can be abstract. D. A subclass can override a concrete method in a superclass to declare it abstract. E. An abstract class can be used as a data type

_____ is a construct that defines objects of the same type. A. A class B. An object C. A method D. A data field

_______ is invoked to create an object. A. A constructor B. The main method C. A method with a return type D. A method with the void return type

___________ is attached to the class of the composing class to denote the aggregation relationship with the composed object. A. An empty diamond B. A solid diamond C. An empty oval D. A solid oval

What is Math.floor(3.6)? A. 3.0 B. 3 C. 4 D. 5.0

A Note floor returns double value

Which of the following statements are correct? A. new Scene(new Button("OK")); B. new Scene(new Circle()); C. new Scene(new ImageView()); D. new Scene(new Pane());

A and D

Which of the following statements are true? A. A default constructor is provided automatically if no constructors are explicitly declared in the class. B. At least one constructor must always be defined explicitly. C. Every class has a default constructor. D. The default constructor is a no-arg constructor

A and D

Analyze the following code. int count = 0; while (count < 100) { // Point A System.out.println("Welcome to Java!"); count++; // Point B } // Point C A. count < 100 is always true at Point A B. count < 100 is always true at Point B C. count < 100 is always false at Point B D. count < 100 is always true at Point C E. count < 100 is always false at Point C

A and E

Which of the following is a valid identifier? A. $343 B. class C. 9X D. 8+9 E. radius

A and E

Which of the following statements convert a double value d into a string s? A. s = (new Double(d)).toString(); B. s = d; C. s = new Double(d).stringOf(); D. s = String.stringOf(d); E. s = d + "";

A and E

Which of the following statements are true? A. Multiple constructors can be defined in a class. B. Constructors do not have a return type, not even void. C. Constructors must have the same name as the class itself. D. Constructors are invoked using the new operator when an object is created

A, B, C and D

Why is JavaFX preferred? A. JavaFX is much simpler to learn and use for new Java programmers. B. JavaFX provides a multi-touch support for touch-enabled devices such as tablets and smart phones. C. JavaFX has a built-in 3D, animation support, video and audio playback, and runs as a standalone application or from a browser. D. JavaFX incorporates modern GUI technologies to enable you to develop rich Internet applications

A, B, C and D

Which of the following statements are true? A. A primary stage is automatically created when a JavaFX main class is launched. B. You can have multiple stages displayed in a JavaFX program. C. A stage is displayed by invoking the show() method on the stage. D. A scene is placed in the stage using the addScene method E. A scene is placed in the stage using the setScene method

A, B, C and E

Which of the following statements will convert a string s into i of int type? A. i = Integer.parseInt(s); B. i = (new Integer(s)).intValue(); C. i = Integer.valueOf(s).intValue(); D. i = Integer.valueOf(s); E. i = (int)(Double.parseDouble(s));

A, B, C, D and E

An instance of _________ describes the errors caused by your program and external circumstances. These errors can be caught and handled by your program. A. RuntimeException B. Exception C. Error D. Throwable E. NumberFormatException

An object is an instance of a __________. A. program B. class C. method D. data

Arguments to methods always appear within __________. A. brackets B. parentheses C. curly braces D. quotation marks

Assume double[][] x = new double[4][5], what are x.length and x[2].length? A. 4 and 4 B. 4 and 5 C. 5 and 4 D. 5 and 5

Object-oriented programming allows you to derive new classes from existing classes. This is called ____________. A. encapsulation B. inheritance C. abstraction D. generalization

Suppose you create a class Square to be a subclass of GeometricObject. Analyze the following code: class Square extends GeometricObject { double length; Square(double length) { GeometricObject(length); } } A. The program compiles fine, but you cannot create an instance of Square because the constructor does not specify the length of the Square. B. The program has a compile error because you attempted to invoke the GeometricObject class's constructor illegally. C. The program compiles fine, but it has a runtime error because of invoking the Square class's constructor illegally

The signature of a method consists of ____________. A. method name B. method name and parameter list C. return type, method name, and parameter list D. parameter list

To obtain the sine of 35 degrees, use _______. A. Math.sin(35) B. Math.sin(Math.toRadians(35)) C. Math.sin(Math.toDegrees(35)) D. Math.sin(Math.toRadian(35)) E. Math.sin(Math.toDegree(35))

What is the output of Integer.parseInt("10", 2)? A. 1; B. 2; C. 10; D. Invalid statement;

Which of the following declares an abstract method in an abstract Java class? A. public abstract method(); B. public abstract void method(); C. public void abstract method(); D. public void method() {} E. public abstract void method() {}

_________ represents an entity in the real world that can be distinctly identified. A. A class B. An object C. A method D. A data field

Analyze the following code: public class Test { public static void main(String[] args) { boolean[][] x = new boolean[3][]; x[0] = new boolean[1]; x[1] = new boolean[2]; x[2] = new boolean[3]; System.out.println("x[2][2] is " + x[2][2]); } } A. The program has a compile error because new boolean[3][] is wrong. B. The program has a runtime error because x[2][2] is null. C. The program runs and displays x[2][2] is null. D. The program runs and displays x[2][2] is true. E. The program runs and displays x[2][2] is false

Analyze the following code: public class Test extends A { public static void main(String[] args) { Test t = new Test(); t.print(); } } class A { String s; A(String s) { this.s = s; } public void print() { System.out.println(s); } } A. The program does not compile because Test does not have a default constructor Test(). B. The program has an implicit default constructor Test(), but it cannot be compiled, because its super class does not have a default constructor. The program would compile if the constructor in the class A were removed. C. The program would compile if a default constructor A(){ } is added to class A explicitly. D. The program compiles, but it has a runtime error due to the conflict on the method name print.

B and C

Every JavaFX main class __________. A. implements javafx.application.Application B. extends javafx.application.Application C. overrides start(Stage s) method D. overrides start() method

B and C

Which of the following statements are true? A. A subclass is a subset of a superclass. B. A subclass is usually extended to contain more functions and more detailed information than its superclass. C. "class A extends B" means A is a subclass of B. D. "class A extends B" means B is a subclass of A

B and C

Which of the following is a possible output from invoking Math.random()? A. 3.43 B. 0.5 C. 0.0 D. 1.0

B and C Math.random( ) returns a real value between 0.0 and 1.0, excluding 1.0

Analyze the following code: public class A extends B { } class B { public B(Strign s) { } } A. The program has a compile error because A does not have a default constructor. B. The program has a compile error because the default constructor of A invokes the default constructor of B, but B does not have a default constructor. C. The program would compile fine if you add the following constructor into A: A(String s) { } D. The program would compile fine if you add the following constructor into A: A(String s) { super(s); }

B and D

Suppose A is an abstract class, B is a concrete subclass of A, and both A and B have a no-arg constructor. Which of the following is correct? A. A a = new A(); B. A a = new B(); C. B b = new A(); D. B b = new B();

B and D

Why do computers use zeros and ones?

Because digital devices have two stable states and it is natural to use one state for 0 and the other for 1

All Java applications must have a method __________. A. public static Main(String[] args) B. public static Main(String args[]) C. public static void main(String[] args) D. public void main(String[] args) E. public static main(String[] args)

An instance of _________ describes system errors. If this type of error occurs, there is little you can do beyond notifying the user and trying to terminate the program gracefully. A. RuntimeException B. Exception C. Error D. Throwable E. NumberFormatException

Assume int[][] x = {{1, 2}, {3, 4}, {5, 6}}, what are x.length are x[0].length? A. 2 and 1 B. 2 and 2 C. 3 and 2 D. 2 and 3 E. 3 and 3

Each time a method is invoked, the system stores parameters and local variables in an area of memory, known as _______, which stores elements in last-in first-out fashion. A. a heap B. storage area C. a stack D. an array

How many elements are array matrix (int[][] matrix = new int[5][5])? A. 14 B. 20 C. 25 D. 30

How many times will the following code print "Welcome to Java"? int count = 0; do { System.out.println("Welcome to Java"); count++; } while (count < 10); A. 8 B. 9 C. 10 D. 11 E. 0

How many times will the following code print "Welcome to Java"? int count = 0; do { System.out.println("Welcome to Java"); } while (++count < 10); A. 8 B. 9 C. 10 D. 11 E. 0

How many times will the following code print "Welcome to Java"? int count = 0; while (count < 10) { System.out.println("Welcome to Java"); count++; } A. 8 B. 9 C. 10 D. 11 E. 0

How many times will the following code print "Welcome to Java"? int count = 0; while (count++ < 10) { System.out.println("Welcome to Java"); } A. 8 B. 9 C. 10 D. 11 E. 0

The java.lang.Number and its subclasses are introduced in Chapter 11. Analyze the following code. Number numberRef = new Integer(0); Double doubleRef = (Double)numberRef; Which of the following statements is correct? A. There is no such class named Integer. You should use the class Int. B. The compiler detects that numberRef is not an instance of Double. C. A runtime class casting exception occurs, since numberRef is not an instance of Double. D. The program runs fine, since Integer is a subclass of Double. E. You can convert an int to double, so you can cast an Integer instance to a Double instance

The keyword __________ is required to declare a class. A. public B. private C. class D. All of the above

What is the correct term for numbers[99]? A. index B. index variable C. indexed variable D. array variable E. array

The following code causes Java to throw _________. int number = Integer.MAX_VALUE + 1; A. RuntimeException B. Exception C. Error D. Throwable E. no exceptions

What is the output of running class C? class A { public A() { System.out.println( "The default constructor of A is invoked"); } } class B extends A { public B() { System.out.println( "The default constructor of B is invoked"); } } public class C { public static void main(String[] args) { B b = new B(); } } A. Nothing displayed B. "The default constructor of B is invoked" C. "The default constructor of A is invoked" followded by "The default constructor of B is invoked" D. "The default constructor of B is invoked" followed by "The default constructor of A is invoked" E. "The default constructor of A is invoked"

What is the value in count after the following loop is executed? int count = 0; do { System.out.println("Welcome to Java"); } while (count++ < 9); System.out.println(count); A. 8 B. 9 C. 10 D. 11 E. 0

Which of the following class definitions defines a legal abstract class? A. class A { abstract void unfinished() { } } B. class A { abstract void unfinished(); } C. abstract class A { abstract void unfinished(); } D. public class abstract A { abstract void unfinished(); }

Which of the following code displays the area of a circle if the radius is positive. A. if (radius != 0) System.out.println(radius * radius * 3.14159); B. if (radius >= 0) System.out.println(radius * radius * 3.14159); C. if (radius > 0) System.out.println(radius * radius * 3.14159); D. if (radius <= 0) System.out.println(radius * radius * 3.14159);

What is 1 - 0.1 - 0.1 - 0.1 - 0.1 - 0.1 == 0.5? A. true B. false C. There is no guarantee that 1 - 0.1 - 0.1 - 0.1 - 0.1 - 0.1 == 0.5 is true

C Since the expression involves floating-point numbers and floating-point numbers are approximated

Which of the following statements is correct? A. Integer.parseInt("12", 2); B. Integer.parseInt(100); C. Integer.parseInt("100"); D. Integer.parseInt(100, 16); E. Integer.parseInt("345", 8);

C and E

A Java exception is an instance of __________. A. RuntimeException B. Exception C. Error D. Throwable E. NumberFormatException

Analyze the following statement: double sum = 0; for (double d = 0; d < 10;) { d += 0.1; sum += sum + d; } A. The program has a compile error because the adjustment is missing in the for loop. B. The program has a compile error because the control variable in the for loop cannot be of the double type. C. The program runs in an infinite loop because d < 10 would always be true. D. The program compiles and runs fine.

How many times will the following code print "Welcome to Java"? int count = 0; do { System.out.println("Welcome to Java"); } while (count++ < 10); A. 8 B. 9 C. 10 D. 11 E. 0

If you declare an array double[] list = {3.4, 2.0, 3.5, 5.5}, the highest index in array list is __________. A. 0 B. 1 C. 2 D. 3 E. 4

The following code fragment reads in two numbers: Scanner input = new Scanner(System.in); int i = input.nextInt(); double d = input.nextDouble(); What is the incorrect way to enter these two numbers? A. Enter an integer, a space, a double value, and then the Enter key. B. Enter an integer, two spaces, a double value, and then the Enter key. C. Enter an integer, an Enter key, a double value, and then the Enter key. D. Enter a numeric value with a decimal point, a space, an integer, and then the Enter key.

What is Math.rint(3.5)? A. 3.0 B. 3 C. 4 D. 4.0 E. 5.0

D Note rint returns nearest even int as a double since 3.5 is equally close to 3.0 and 4.0

What is the output of running class Test? public class Test { public static void main(String[] args) { new Circle9(); } } public abstract class GeometricObject { protected GeometricObject() { System.out.print("A"); } protected GeometricObject(String color, boolean filled) { System.out.print("B"); } } public class Circle9 extends GeometricObject { /** No-arg constructor */ public Circle9() { this(1.0); System.out.print("C"); } /** Construct circle with a specified radius */ public Circle9(double radius) { this(radius, "white", false); System.out.print("D"); } /** Construct a circle with specified radius, filled, and color */ public Circle9(double radius, String color, boolean filled) { super(color, filled); System.out.print("E"); } } A. ABCD B. BACD C. CBAE D. AEDC E. BEDC

What is the output of the following JavaFX program? import javafx.application.Application; import javafx.stage.Stage; public class Test extends Application { public Test() { System.out.println("Test constructor is invoked."); } @Override // Override the start method in the Application class public void start(Stage primaryStage) { System.out.println("start method is invoked."); } public static void main(String[] args) { System.out.println("launch application."); Application.launch(args); } } A. launch application. start method is invoked. B. start method is invoked. Test constructor is invoked. C. Test constructor is invoked. start method is invoked. D. launch application. start method is invoked. Test constructor is invoked. E. launch application. Test constructor is invoked. start method is invoked

Which of the following is not permanent storage devices? A) floppy disk B) hard disk C) flash stick D) CD-ROM E) main memory

Which of the following statements regarding abstract methods is false? A. Abstract classes have constructors. B. A class that contains abstract methods must be abstract. C. It is possible to declare an abstract class that contains no abstract methods. D. An abstract method cannot be contained in a nonabstract class. E. A data field can be declared abstract

java final

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