Intro to Java Programming

Which of the following can be used to concatenate two String objects? Select one: A. appendString() B. concatenate() C. == D. +=

+=

What is the output of the following code? int x = 0;int y = 0;while ( x < 3 ){if ( x <= 2 ){x++;break;}y = x;x++;} System.out.println( y ); Select one: A. 0 B. 1 C. 2 D. 3

0

What is the output of the following statements? int x = 10;int y = 5;if ( ( x + 1 ) < 12 && y > 5 )x += 2;elsex = 0;System.out.println( x ); Select one: A. 0 B. 10 C. 12 D. 13

0

What is the output of this program? public class JavaProgram{public static void main( String [] args ){int x = 2;int y = 2;int z = 3;boolean result = ( ( z - ( x + 2 ) ) == ( y + 1 ) );System.out.println( result );}} Select one: A. true B. false C. -1 D. 3

false

Which JDK command will compile a Java program named YourProgram? Select one: A. java YourProgram B. java YourProgram.java C. javac YourProgram.java D. javac YourProgram

javac YourProgram.java

What is the output of the following program? public class MyProgram{ public static void main( String [] args ) { String [] array = { "Java rocks", "the world" }; myMethod( array[0] ); myMethod( array[1] ); } public static void myMethod( String s ) { String myString = s.substring( 6, 8 ); System.out.print( myString + "|" ); }} Select one: A. ock|rld| B. ck|ld| C. c|l| D. oc|rl|

oc|rl|

What is the output of the following program? public class 6Times2{public static void main( String [] args ){System.out.println( "6 times 2 is 12" );}} Select one: A. "6 times 2 is 12" B. 6 times 2 is 12 C. The program will not compile D. The program will compile, but it will produce a runtime error

The program will not compile

What is the value of x and y in the print statement? int x = 5;int y = 10;if ( ( x == 5 ) || ( x + y ) > 20 )x = 1;y = 0;elsex = 0;y = 1; System.out.println( x + " " + y ); Select one: A. x = 1 y = 0 B. x = 0 y = 1 C. x = 5 y = 10 D. The statements will not compile

The statements will not compile

Which of the following is not an advantage of using methods? Select one: A. Using methods makes programs run faster B. Using methods makes reusing code easier C. Using methods makes programs easier to read D. Using methods hides the implementation details from clients

Using methods makes programs run faster

Which of these keywords is not allowable when declaring a class data member? Select one: A. public B. private C. protected D. abstract E. final

abstract

A Java program block is enclosed in __________. Select one: A. parentheses () B. braces {} C. brackets [] D. quotes " "

braces

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

false

What is the output of the following statements? float y = 0F;for ( int x = 1; x != 5; x++ )y /= x;System.out.println( y ); Select one: A. 0.0 B. 5.0 C. 10.0 D. 250.0

0.0

What is the binary number equivalent of the decimal number 23? Select one: A. 00001111 B. 00101011 C. 00010111 D. 00011001

00010111

What is the output of this program? public class MyProgram{public static void main( String [] args ){int x = 10;change( x );System.out.println( x );}public static int change( int x ){x = 99;return x;}} Select one: A. 99 B. 10 C. 0 D. Something other than the above choices

10

What is the value of s after the statement String s = "1" + 2 + 3 + "Java"; is executed? Select one: A. 15Java B. 6Java C. 123Java D. The statement is illegal

123Java

What is the output of the following code segment? for(int i = 1; i <= 10; i++ ){ System.out.print( i + " " ); i++;} Select one: 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

13579

What is the output of this program? public class JavaProgram{public static void main( String [] args ){int x = 10;int y = 17;float z = (float) (x + (float) y / 2 );System.out.println( z );}} Select one: A. 17.0 B. 17.5 C. 18.0 D. 18.5

18.5

What is the output of this program? public class JavaProgram{public static void main( String [] args ){int x = 0;switch ( x ){case 0:case 1:x = 0;case 2:x = 2 + x;break;case 3:x = 3 + x;}System.out.println( x ); }} Select one: A. 0 B. 2 C. 3 D. 6 Feedback

2

The expression 5 + 21 / (4 - 2) * 2 evaluates to __________. Select one: A. 20 B. 24 C. 25 D. 26

25

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

3 and 2

What is the result of 39 / 6? Select one: A. 3 B. 6 C. 6.5 D. 7

6

What does the expression (int) (76.0252175 * 100) / 100 evaluate to? Select one: A. 76.02 B. 76 C. 76.0252175 D. 76.03

76

If x is 12, what is the value of x << 3? Select one: A. 32 B. 64 C. 96 D. 128

96

A class method named myMethod accepts a char argument named y and returns the value of an integer variable named x. Which Java keywords and statements will be used the method's definition? (select all that apply) Select one or more: A. int x; B. static C. void D. char y E. return

A, B, D, and E

Which of the following is accomplished in the Java statement int myVariable; ? (select all that apply) Select one or more: A. The name myVariable is made known to a portion of the program. B. The data type int is associated with myVariable. C. The value of myVariable is initialized to zero by default. D. The value of myVariable is not initialized.

A,B, and D

What is the output of the following code? public static void main( String [] args ){ double [] myArray = { 1, 5, 5, 5, 5, 1 }; double max = myArray[0]; int maxIndex = 0; for( int i = 1; i < myArray.length; i++ ) if( myArray[i] > max ) { max = myArray[i]; maxIndex = i; } System.out.println( maxIndex );} Select one: A. 0 B. 1 C. 2 D. 3 E. 4

B

Which of the following are types of Java methods? (select all that apply) Select one or more: A. global methods B. Instance methods C. external methods D. class methods

B and D

Which of the following statements is true? Select one: A. The portion of a program over which a variable is known and can be referenced is called a variable's duration. B. The portion of a program over which a variable is known and can be referenced is called a variable's lifetime. C. The portion of a program over which a variable is known and can be referenced is called a variable's scope. D. None of the above are true.

C. The portion of a program over which a variable is known and can be referenced is called a variable's scope.

Select the item that doesn't belong on the list. A. software B. machine language C. JVM D. bytecode E. CPU

E

What is the output of the following program? public class MyProgram{public static void main( String [] args ){String s = "Java";StringBuffer buffer = new StringBuffer( s );change( s );System.out.println( s );} public static void change( String s ){s = "Java Rocks";}} Select one: A. Java B. Java Rocks C. Rocks D. Nothing is displayed

Java

The Java compiler translates source code into __________. Select one: A. Java bytecode B. machine code C. assembly language code D. none of the above

Java bytecode

What was the original name for the Java language? Select one: A. Java B. Oak C. Maple D. D

Oak

Assume that a writeData() method is added to MyClass. public class MyClass{private int x;private int y; public MyClass(){x = 0;y = 0;}public int getX() { return x; }public int getY() { return y; }public void writeData() { /* missing code */ }} Which of the following would be incorrectly substituted for the missing code? Select one: A. System.out.println( x + " " + y ); B. System.out.println( getX() + " " + getY() ); C. System.out.println( this ); D. System.out.println( this.getX() + " " + this.getY() );

System.out.println( this );

Which of the following statements produce the same result? I. x -= x + 4; II. x = x + 4 -x; III. x = x - (x + 4); Select one: A. I and II B. I and III C. II and III D. I, II, and III

| and |||

If x = 10 and y = 10, what is the value of x | y? Select one: A. 0 B. 1 C. 8 D. 10

10

What is the value of y after the following statements are executed? int x = -2;int z = -1; int y = ( x > z ) ? 10 : 2; Select one: A. 0 B. -1 C. 2 D. 10

2

Assume that s1 and s2 are two String objects. Which of the following are correct? (select all that apply) Select one or more: A. String s = new String( "new String" ); B. String s3 = s1 + s2; C. int i = s1.length; D. s2.charAt( 0 ) = '5';

A and B

Which of the following are correct ways to declare variables? (select all that apply) Select one or more: A. int i; int j; B. int i, j, k; C. int i; j; D. int i, int j;

A and B

Which of the following are valid Java variable names? (select all that apply) Select one or more: A. Hello B. test_score C. 4ere D. 5+5 E. float

A and B

Which of the following is a constant, according to recommended Java naming conventions? (select all that apply) Select one or more: A. MAX_VALUE B. Test C. read D. ReadInt E. COUNT

A and E

__________ is a construct that defines objects of the same type. Select one: A. A class B. An object C. A method D. An attribute

A class

Which of the following are storage devices? Select one or more: A. floppy disk B. hard disk C. flash drive D. CD-ROM

A, B, C, and D

Which of the following are Java primitive types? (select all that apply) Select one or more: A. int B. double C. bool D. float E. short F. unsigned G. byte

A, B, D, E, and G

Which of these statements add 1 to a variable named x? (select all that apply) Select one or more: A. x = 1 + x; B. x = x + 1; C. ++x; D. x =+ x;

A,B, and C

Which of the following statements are true? (select all that apply) Select one or more: A. Java variables may be defined anywhere in a method provided they are defined before being used. B. A variable named x and a variable named X are considered to be different variables in Java. C. Java variable names are limited to 32 characters. D. Java variables must be initialized before they are used.

A,C, and D

Which of the following are valid Java comments? (select all that apply) Select one or more: A. /** comments // B. // comments C. /* comments */ D. ** comments **

B and C

For the class below, which of the following will cause an error message? public class MyClass{private int x; public MyClass() { x = 0; }public MyClass( int d ) { x = d; }public void setData( int d ) { x = d; }} Select one: A. MyClass obj1 = new MyClass( 10 );MyClass obj2 = obj1; B. MyClass obj1 = null;MyClass obj2 = obj1; C. MyClass obj1 = null;obj1.setData( 2 ); D. None of the above will cause an error

MyClass obj1 = null; obj1.setData( 2 );

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

37 % 6

What is the output of the following statements? int x = 6;do{if ( x == 0 )x = 1;x--;} while ( x != 4 );System.out.println( x ); Select one: A. 1 B. 2 C. 3 D. 4

4

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

4

What is the output of the following program? public class MyProgram{ public static void main( String [] args ) { int [][] array = { {3, 4, 5, 1}, {34, 6, 1, 2} }; for( int i = 0; i < array.length; i++ ) System.out.print( myMethod( array[i] ) + " " ); } public static int myMethod( int [] arr ) { int v = arr[0]; for( int i = 1; i < arr.length; i++ ) if ( v < arr[i] ) v = arr[i]; return v; }} Select one: A. 3 34 B. 1 1 C. 5 6 D. 5 34 E. 34 5

5 34

What is the output of the following code? public class MyProgram{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" );elseSystem.out.println( "s1 and s2 reference to different String objects" );}} Select one: A. s1 and s2 reference to the same String object B. s1 and s2 reference to different String objects C. The program will not compile D. The program will compile, but will produce a runtime error

s1 and s2 reference to different String objects

Which of the following is the correct way to write the header for a main method? Select one: 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 )

public static void main( String [] args )

If a method does not return a value, which of the following keywords can be used as its return type? Select one: A. void B. int C. public D. None of the above

void

What is the output of this program? public class JavaProgram{public static void main( String [] args ){int x = 20;int y = 10;if ( x < y ){if ( y == 20 )y = 0;}else {y = y;}System.out.println( "x = " + x + " y = " + y );}} Select one: A. x = 20 y = 10 B. x = 10 y = 0 C. The program will not compile and run D. Other

x = 20 y = 10

What is the output of the following program? public class MyProgram{ public static void main( String [] args ) { int [] x = { 1, 2, 3, 4 }; int [] y = { 1, 3, 4, 5 }; swap( x, 3 ); for( int i = 0; i < x.length; i++ ) System.out.print( x[i] + " " ); System.out.println();} public static void swap( int [] a , int n ) { for( int i = 0; i < a.length; i++ ) { if ( a[i] <= n ) a[i] = 0; } } } Select one: A. 1 2 3 4 B. 0 1 2 3 C. 0 0 3 4 D. 0 0 0 4

0 0 0 4

What is the output of the following program? public class MyProgram{ public static void main( String [] args ) { int [][] array1 = { {1, 2}, {3, 4} }; int [][] array2 = myMethod( array1 ); int sz = array2[0].length; for( int i = 0; i < sz; i++ ) { for( int j = 0; j < sz; j++ ) System.out.print( array2[i][j] + " " ); System.out.println(); } } public static int[][] myMethod( int [][] a ) { int sz = a[0].length; int [][] result = new int[sz][sz]; for( int i = 0; i < sz; i++ ) for( int j = 0; j < sz; j++ ) if( i == j ) result[i][j] = a[i][j]; else result[i][j] = 0; return result; }} Select one: A. 1 00 4 B. 0 23 0 C. 4 00 1 D. 0 32 0

1 0 0 4

How many times is the print statement executed in the following code segment? int count = 0;int j = 0;for( int i = 0; i <= 10; i++ ) while( j < i ) { count++; System.out.println( count ); j++; } Select one: A. 5 B. 9 C. 10 D. 11

10

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

10

What is the output of the following program? public class MyProgram{public static void main( String [] args ){int x = 10;int y = 20;swap( x, y );System.out.println( x + " " + y );} public static void swap( int a, int b ){int temp; if ( a > b ){temp = a;a = b;b = temp;}}} Select one: A. 10 20 B. 20 10 C. The program won't compile D. The program will compile, but a runtime error will be produced

10 20

What is the value of count after the following code executes? int count = 10; while( ++count < 9 ){System.out.print(count);} Select one: A. 9 B. 10 C. 11 D. 12

11

What is the output of the following code segment? for( int i = 1; i < 5; i++ ) for( int j = 1; j < i; j++ ) System.out.print( j + " " ); Select one: A. 1 1 2 1 2 2 B. 1 1 2 1 2 3 C. 1 1 2 1 2 1 D. 1 1 2 1 1 1

112123

What is the output of the following code segment? for( int i = 1; i < 10; i++ ){ for( int j = 0; j < 3; j++ ) { if( i % 2 == 0 ) { System.out.print( i + " " ); continue; } }} Select one: A. 2 2 2 4 4 4 6 6 6 8 8 8 B. 2 2 2 3 3 3 6 6 6 8 8 8 C. 1 1 1 2 2 2 4 4 4 6 6 6 D. 1 1 1 3 3 3 5 5 5 6 6 6

2 2 2 4 4 4 6 6 6 8 8 8

What is the output of this program? public class JavaProgram{public static void main( String [] args ){int x = 10;int y = 12;float f = 5F;float z = y / x * f; System.out.println( z );} } Select one: A. 0 B. 6.0 C. 5.0 D. The program will not compile and run

5.0

What is the output of the following statements? boolean birthday = true;int age = 64; if( birthday == true && age++ >= 65 ) System.out.println( age );else System.out.println( --age ); Select one: A. 64 B. 65 C. 66 D. Output is other than the above choices

64

What is the output of the following statements? int x = 0;while ( ++x <= 7 )x++;System.out.println( x ); Select one: A. 6 B. 7 C. 8 D. 9

9

The "less than or equal to " comparison operator in Java is __________. Select one: A. < B. <= C. =< D. <<

<=

The equal comparison operator in Java is __________. Select one: A. = B. != C. == D. ^=

==

Which of the following assignment statements is correct? Select one or more: A. i = j = k = 1; B. i = 1, j = 1; k = 1; C. i = 1 = j = 1 = k = 1; D. i == j == k == 1;

A

Which program statements contain errors? (select all that apply) 1 public static void myMethod( x )2 {3 int x;4 int y = 10;5 System.out.println( ( x + y ) );6 } Select one or more: A. 1 B. 2 C. 3 D. 4 E. 5 F. 6 G. All statements are correct

A

Which of the following statements is false? (select all that apply) Select one or more: A. A class and an object are the same thing B. It is common practice to give most methods in a class private access C. It is common practice to give most data members private access D. Java will always provide a default constructor for a class

A and B

Which statement creates an integer array that models this table? (select all that apply) 1 2 3 4 5 6 Select one or more: A. int a[][] = { {1, 2}, {3, 4}, {5, 6} }; B. int a[3]2] = {1, 2, 3, 4, 5, 6}; C. int [][] a = { {1, 2}, {3, 4}, {5, 6} }; D. int a[3][2] = { {1, 2}, {3, 4}, {5, 6} };

A and C

Which of the following statements are true? (select all that apply) Select one or more: A. The Java compiler translates source code into machine language that can be directly executed on a computer. B. The output file produced by the Java compiler is architecturally neutral. C. A Java program named MyProgram should be stored in a file named MyProgram.java. D. The Java language is a high-level programming language.

A and D

Which of the following is true? Select one: A. A declaration statement initializes the value of a variable to a default value. B. A declaration statement does not initialize the value of a variable to a default value. C. Java will automatically initialize the value of integer variables to zero. D. None of the above

A declaration statement does not initialize the value of a variable to a default value.

Which of the following statements are true? (select all that apply) Select one or more: A. A class can have multiple constructors B. Constructors do not have a return type C. Constructors must have the same name as the class D. Constructors are invoked using the new operator when an object is created

All

Which of the following statements create and allocate storage for a two-dimensional array of type double? (select all that apply) Select one or more: A. double d[5][10]; B. double [][] d = new double[20][20]; C. double d[][] = { {1,2}, {3,4} }; D. double d = new double[2][3];

B and C

Which of the following statements are incorrect? (select all that apply) Select one or more: A. double [] d = new double[5]; B. double d[] = new double[5]; C. double d[] = new double(5); D. double d = new double[5];

C and D

Which of the following will add number to sum? (select all that apply) Select one or more: A. number += sum; B. number = sum + number; C. sum += number; D. sum = sum + number;

C and D

__________ is considered to be the brain of a computer. Select one: A. hardware B. CPU C. memory D. disk drive

CPU

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

D

What is the output of the following program? public class MyProgram{public static void main( String [] args ){String s = "Hello";StringBuffer buffer = new StringBuffer( s );change( buffer );System.out.println( buffer ); } public static void change( StringBuffer buff ){buff.append( " World" );}} Select one: A. Hello B. Hello World C. World D. Nothing is displayed

Hello World

For the Java program below, what file name should the source code be stored in? public class MyProg{System.out.println( "Hello World" );} Select one: A. MyProg.txt B. MyProg.docx C. MyProg.java D. Any file name with a .java extension

MyProg.java

If a method has the heading public static double [][] myMethod(), what return statement may be used in myMethod()? Select one: A. return 10; B. return {1, 2, 3}; C. return new double[] { 1, 2, 3}; D. return new double[3] {1, 2, 3}; E. None of the above

None of the above

What is the output of the following code? // source file MyProgram.javapublic class MyProgram{public static void main( String [] args ){A a = new A();a.print();}} // source file A.javapublic class A{String s = "hello";public A( String str ) { s = str; }public void print(){System.out.println( s );} } Select one: A. The program has a compilation error because s is not public B. The program has a compilation error because A doesn't have a default constructor C. The program will compile, but will produce a runtime error D. The program will compile and run just fine

The program has a compilation error because A doesn't have a default constructor

What is the output of the following program? public class MyProgram{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 ] + " " );}} Select one: A. 0 1 2 3 4 B. 4 C. The program has a runtime error D. The program has a compile error

The program has a runtime error

What is the output of the program below when it is executed from the command line as java MyProgram Java Rocks? public class MyProgram{ public static void main( String [] args ) { System.out.println( args[0] + " " + args[1] + " " + args[2] ); }} Select one: A. java MyProgram Java B. MyProgram Java Rocks C. Java Rocks D. The program will have a runtime error

The program will have a runtime error

What is the output of the following program? public class MyProgram{public static void main( String [] args ){float x = 10F;System.out.println( myMethod( x ) );} public static void myMethod( float x ){if ( x < 10 )return 0;elsereturn 2 * x;}} Select one: A. 0.0 B. 10.0 C. 20.0 D. The program will not compile

The program will not compile

What is the output of this program? public class JavaProgram{public static void main( String [] args ){int x = 10;if ( x = 10 )System.out.println( "true" );elseSystem.out.println( "false" );}} Select one: A. true B. false C. The program will not compile D. Other

The program will not compile

What is the output of this program? public class MyProgram{public static void main( String [] args ){int x = 20;x = myMethod( x );System.out.println( x );}public static int myMethod( float n ){return 2 * n;}} Select one: A. 0 B. 20 C. 40 D. The program will not compile

The program will not compile

What is the output of the following code? public static void main( String [] args ){int a;int b = 10;a = 9;c = a + b;System.out.println( a + "\t" + b + "\t" + c );} Select one: A. 9 10 19 B. a = 9 b = 10 c = 19 C. The program will not compile and run D. The program will compile, but a runtime error will be generated

The program will not compile and run

What is the output of the following program? public class JavaProgram{ public static void main( String [] args ) { int x = 0; if ( x != 0 ) System.out.print( "x is " + x ); System.out.print( " : test was true" ); else System.out.print( "x is " + x ); System.out.println( " : the test was false" ); }} Select one: A. x is -1 : the test was true B. x is 1 : the test was false C. The program will not compile and run D. Other

The program will not compile and run

What is the output of this program? public class JavaProgram{public static void main( String [] args ){int c1 = 1;int c2 = 2;int x = 3;switch ( x ){case c1:case c2:x = 0;case 3:default:x = 2 * x;}System.out.println( x );}} Select one: A. 3 B. 6 C. 0 D. The program will not compile and run

The program will not compile and run

What is the output of the following program? public class MyProgram{public static void main( String [] args ){String s;System.out.println( "s is " + s );}} Select one: A. The program will not compile due to an initialization problem B. The program will compile, but there will be a runtime error due to an initialization problem C. The program will compile, but there will be a runtime error because s is null D. The program will compile and run just fine

The program will not compile due to an initialization problem

For the following code, which of the statements below is true? // source file MyProgram.javapublic class MyProgram{public static void main( String args[] ){MyClass obj = new MyClass();obj.data++;}} // source file MyClass.javapublic class MyClass{private int data;public MyClass() { data = 0; }} Select one: A. The program won't compile because the class constructor is incorrect B. The program won't compile because the argument in the main method is wrong C. The program won't compile because data is private D. The program compiles and runs fine

The program won't compile because data is private

What is the output of the following statements? int x = 10;if ( (x += 10) >= 10 )System.out.println( "True" );elseSystem.out.println( "False" ); Select one: A. True B. False C. The program will not compile and run D. The program will compile, but it will terminate abnormally when run

True

What is the output of the following code? String s = "bagadonuts";s.replace( "a", "ZZ" ); System.out.println( s ); Select one: A. bagadonuts B. bZZgadonuts C. bagXXdonuts D. bZZgZZdonuts

bagadonuts

The statement (int) ( Math.random() * (50 + 1) ) returns a random number __________. Select one: A. between 0 and 50 B. between 0 and 51 C. between 1 and 50 D. between 1 and 51

between 0 and 50