PRO192
10. Is it possible to define a class called Thing so that the following method can return true under certain circumstances? boolean weird(Thing s) { Integer x = new Integer(5); return s.equals(x); } A. Yes B. No
A
12. Suppose a source file contains a large number of import statements and one class definition. How do the imports affect the time required to load the class? A. Class loading takes no additional time. B. Class loading takes slightly more time. C. Class loading takes significantly more time.
A
12. Suppose salaries is an array containing floats. Which of the following are valid loop control statements for processing each element of salaries? A. for (float f:salaries) B. for (int i:salaries) C. for (float f::salaries) D. for (int i::salaries)
A
13. Suppose the declared type of x is a class, and the declared type of y is an interface. When is the assignment x = y; legal? A. When the type of x is Object B. When the type of x is an array C. Always D. Never
A
14. Suppose the type of xarr is an array of XXX, and the type of yarr is an array of YYY. When is the assignment xarr = yarr; legal? A. Sometimes B. Always C. Never
A
14. Which statement is true about the following method? int selfXor(int i) { return i ^ i; } A. It always returns 0. B. It always returns 1. C. It always an int where every bit is 1. D. The returned value varies depending on the argument.
A
18. Which of the following may appear on the left-hand side of an instanceof operator? A. A reference B. A class C. An interface D. A variable of primitive type
A
19. When does an exception's stack trace get recorded in the exception object? A. When the exception is constructed B. When the exception is thrown C. When the exception is caught D. When the exception's printStackTrace() method is called
A
20. What is the difference between the rules for method-call conversion and the rules for assignment conversion? A. There is no difference; the rules are the same. B. Method-call conversion supports narrowing, assignment conversion does not. C. Assignment conversion supports narrowing, method-call conversion does not. D. Method-call conversion supports narrowing if the method declares that it throws ClassCastException.
A
3. What is the minimal modification that will make this code compile correctly? 1. final class Aaa 2. { 3. int xxx; 4. void yyy() { xxx = 1; } 5. } 6. 7. 8. class Bbb extends Aaa 9. { 10. final Aaa finalref = new Aaa(); 11. 12. final void yyy() 13. { 14. System.out.println("In method yyy()"); 15. finalref.xxx = 12345; 16. } 17. } A. On line 1, remove the final modifier. B. On line 10, remove the final modifier. C. Remove line 15. D. On lines 1 and 10, remove the final modifier. E. The code will compile as is. No modification is needed.
A
3. Which of the following expressions results in a positive value in x? A. int x = -1; x = x >>> 5; B. int x = -1; x = x >>> 32; C. byte x = -1; x = x >>> 5; D. int x = -1; x = x >> 5;
A
30. Suppose you are writing a class that provides custom deserialization. The class implements java.io.Serializable (and not java.io.Externalizable). What method should imple- ment the custom deserialization, and what is its access mode? A. private readObject B. public readObject() C. private readExternal() D. public readExternal()
A
5. What is -8 % 5? A. -3 B. 3 C. -2 D. 2
A
8. How can you force garbage collection of an object? A. Garbage collection cannot be forced. B. Call System.gc(). C. Call System.gc(), passing in a reference to the object to be garbage-collected. D. Call Runtime.gc(). E. Set all references to the object to new values (null, for example).
A
This question concerns the following class definition: 1. package abcde; 2. 3. public class Bird { 4. protected static int referenceCount = 0; 5. public Bird() { referenceCount++; } 6. protected void fly() { /* Flap wings, etc. */ } 7. static int getRefCount() { return referenceCount; } 8. } Which statement is true about class Bird and the following class Nightingale? 1. package singers; 2. 3. class Nightingale extends abcde.Bird { 4. Nightingale() { referenceCount++; } 5. 6. public static void main(String args[]) { 7. System.out.print("Before: " + referenceCount); 8. Nightingale florence = new Nightingale(); 9. System.out.println(" After: " + referenceCount); 10. florence.fly(); 11. } 12. } A. The program will compile and execute. The output will be Before: 0 After: 2. B. The program will compile and execute. The output will be Before: 0 After: 1. C. Compilation of Nightingale will fail at line 4 because static members cannot be overridden. D. Compilation of Nightingale will fail at line 10 because method fly() is protected in the superclass. E. Compilation of Nightingale will succeed, but an exception will be thrown at line 10, because method fly() is protected in the superclass.
A
11. Suppose class Supe, in package packagea, has a method called doSomething(). Suppose class Subby, in package packageb, overrides doSomething(). What access modes may Subby's version of the method have? (Choose 2) A. public B. protected C. Default D. private
A, B
17. Which of the following are legal? (Choose 2) A. double d = 1.2d; B. double d = 1.2D; C. double d = 1.2d5; D. double d = 1.2D5;
A, B
14. Which of the following may be declared final? (Choose all that apply.) A. Classes B. Data C. Methods
A, B, C
10. Consider the following code: 1. public class Assertification { 2. public static void main(String[] args) { 3. assert args.length == 0; 4 } 5. } Which of the following conditions must be true in order for the code to throw an AssertionError? Assume you are using release 5.0. (Choose all that apply.) A. The source code must be compiled with the -source 1.5 flag. B. The application must be run with the -enableassertions flag or another assertion- enabling flag. C. The args array must have exactly zero elements. D. The args array must have one or more elements.
A, B, D
13. Which of the following are legal? (Choose all that apply.) A. for (int i=0, j=1; i<10; i++, j++) B. for (int i=0, j=1;; i++, j++) C. for (int i=0, float j=1; ; i++, j++) D. for (String s = ""; s.length()<10; s += '!')
A, B, D
16. Which of the following are legal argument types for a switch statement? A. byte B. int C. long D. float E. char F. String
A, B, E
19. Which of the following operators can perform promotion on their operands? (Choose all that apply.) A. + B. - C. ++ D. -- E. ~ F. !
A, B, E
13. Which of the following are legal import statements? (choose 2) A. import java.util.Vector; B. static import java.util.Vector.*; C. import static java.util.Vector.*; D. import java.util.Vector static;
A, C
4. Which of the following expressions are legal? (Choose 2) A. String x = "Hello"; int y = 9; x += y; B. String x = "Hello"; int y = 9; if (x == y) {} C. String x = "Hello"; int y = 9; x = x + y; D. String x = "Hello"; int y = 9; y = y + x;
A, C
16. Suppose class A has a method called doSomething(), with default access. Suppose class B extends A and overrides doSomething(). Which access modes may apply to B's version of doSomething()? (Choose all that apply.) A. public B. private C. protected D. Default
A, C, D
1. Which of the following declarations are illegal? (Choose 3) A. default String s; B. transient int i = 41; C. public final static native int w(); D. abstract double d; E. abstract final double hyperbolicCosine();
A, D, E
5. Consider the following line of code: int[] x = new int[25]; After execution, which statements are true? (Choose 2) A. x[24] is 0 B. x[24] is undefined C. x[25] is 0 D. x[0] is null E. x.length is 25
A, E
7. Consider the following class hierarchy and code fragment: 1. try { 2. // assume s is previously defined 3. URL u = new URL(s); 4. // in is an ObjectInputStream 5. Object o = in.readObject(); 6. System.out.println("Success"); 7. } 8. catch (MalformedURLException e) { 9. System.out.println("Bad URL"); 10. } 11. catch (StreamCorruptedException e) { 12. System.out.println("Bad file contents"); 13. } 14. catch (Exception e) { 15. System.out.println("General exception"); 16. } 17. finally { 18. System.out.println("Doing finally part"); 19. } 20. System.out.println("Carrying on"); What lines are output if the methods at lines 3 and 5 complete successfully without throwing any exceptions? (Choose all that apply.) A. Success B. Bad URL C. Bad file contents D. General exception E. Doing finally part F. Carrying on
A, E, F
1. A signed data type has an equal number of non-zero positive and negative values available. A. True B. False
B
10. Consider the following code: 1. Raccoon rocky; 2. SwampThing pogo; 3. Washer w; 4. 5. rocky = new Raccoon(); 6. w = rocky; 7. pogo = w; Which of the following statements is true? (Choose one.) A. Line 6 will not compile; an explicit cast is required to convert a Raccoon to a Washer. B. Line 7 will not compile; an explicit cast is required to convert a Washer to a SwampThing. C. The code will compile and run. D. The code will compile but will throw an exception at line 7, because runtime conversion from an interface to a class is not permitted. E. The code will compile but will throw an exception at line 7, because the runtime class of w cannot be converted to type SwampThing.
B
11. Suppose a source file contains a large number of import statements. How do the imports affect the time required to compile the source file? A. Compilation takes no additional time. B. Compilation takes slightly more time. C. Compilation takes significantly more time.
B
11. Suppose ob1 and ob2 are references to instances of java.lang.Object. If (ob1 == ob2) is false, can ob1.equals(ob2) ever be true? A. Yes B. No
B
11. Which of the following is the most appropriate way to handle invalid arguments in a public method? A. Throw java.lang.InvalidArgumentException. B. Throw java.lang.IllegalArgumentException. C. Check for argument validity in an assert statement, which throws AssertionError when the arguments are invalid. D. Use non-assert code to check for argument validity. If invalid arguments are detected, explicitly throw AssertionError.
B
15. When is x & y an int? (Choose one). A. Always B. Sometimes C. When neither x nor y is a float, a long, or a double
B
17. True or false: If class Y extends class X, the two classes are in different packages, and class X has a protected method called abby(), then any instance of Y may call the abby() method of any other instance of Y. A. True B. False
B
17. When is it appropriate to pass a cause to an exception's constructor? A. Always B. When the exception is being thrown in response to catching of a different exception type C. When the exception is being thrown from a public method D. When the exception is being thrown from a private method
B
18. Which of the following should always be caught? A. Runtime exceptions B. Checked exceptions C. Assertion errors D. Errors other than assertion errors
B
2. Which of the following statements is true? A. An abstract class may not have any final methods. B. A final class may not have any abstract methods.
B
6. What is 7 % -4? A. -3 B. 3 C. -4 D. 4
B
7. What results from running the following code? 1. public class Xor { 2. public static void main(String args[]) { 3. byte b = 10; // 00001010 binary 4. byte c = 15; // 00001111 binary 5. b = (byte)(b ^ c); 6. System.out.println("b contains " + b); 7. } 8. } A. The output: b contains 10 B. The output: b contains 5 C. The output: b contains 250 D. The output: b contains 245
B
9. What does the following code do? Integer i = null; if (i != null & i.intValue() == 5) System.out.println("Value is 5"); A. Prints "Value is 5". B. Throws an exception.
B
14. Which of the following may be statically imported? (Choose 2) A. Package names B. Static method names C. Static field names D. Method-local variable names
B, C
19. Which of the following may appear on the right-hand side of an instanceof operator? (Choose 2) A. A reference B. A class C. An interface D. A variable of primitive type E. The name of a primitive type
B, C
2. Which of the following expressions are legal? (Choose 2) A. int x = 6; x = !x; B. int x = 6; if (!(x > 3)) {} C. int x = 6; x = ~x;
B, C
15. Which of the following may follow the static keyword? (Choose all that apply.) A. Class definitions B. Data C. Methods D. Code blocks enclosed in curly brackets
B, C, D
9. Which of the following are appropriate situations for assertions? A. Preconditions of a public method B. Postconditions of a public method C. Preconditions of a private method D. Postconditions of a private method
B, C, D
1. Consider the following code: 1. for (int i = 0; i < 2; i++) { 2. for (int j = 0; j < 3; j++) { 3. if (i == j) { 4. continue; 5. } 6. System.out.println("i = " + i + " j = " + j); 7. } 8. } Which lines would be part of the output? (Choose all that apply.) A. i = 0 j = 0 B. i = 0 j = 1 C. i = 0 j = 2 D. i = 1 j = 0 E. i = 1 j = 1 F. i = 1 j = 2
B, C, D, F
20. Which of the following are true? (Choose 2) A. Primitives are passed by reference. B. Primitives are passed by value. C. References are passed by reference. D. References are passed by value.
B, D
3. Which of the following signatures are valid for the main() method entry point of an application? (Choose all that apply.) A. public static void main() B. public static void main(String arg[]) C. public void main(String [] arg) D. public static void main(String[] args) E. public static int main(String [] arg)
B, D
6. Consider the following class hierarchy and code fragment: 1. try { 2. // assume s is previously defined 3. URL u = new URL(s); 4. // in is an ObjectInputStream 5. Object o = in.readObject(); 6. System.out.println("Success"); 7. } 8. catch (MalformedURLException e) { 9. System.out.println("Bad URL"); 10. } 11. catch (StreamCorruptedException e) { 12. System.out.println("Bad file contents"); 13. } 14. catch (Exception e) { 15. System.out.println("General exception"); 16. } 17. finally { 18. System.out.println("Doing finally part"); 19. } 20. System.out.println("Carrying on"); What lines are output if the constructor at line 3 throws a MalformedURLException? (Choose all that apply.) A. Success B. Bad URL C. Bad file contents D. General exception E. Doing finally part F. Carrying on
B, E, F
1. After execution of the following code fragment, what are the values of the variables x, a, and b? 1. int x, a = 6, b = 7; 2. x = a++ + b++; A. x = 15, a = 7, b = 8 B. x = 15, a = 6, b = 7 C. x = 13, a = 7, b = 8 D. x = 13, a = 6, b = 7
C
12. When a byte is added to a char, what is the type of the result? A. byte B. char C. int D. short E. You can't add a byte to a char.
C
13. When a short is added to a float, what is the type of the result? A. short B. int C. float D. You can't add a short to a float.
C
15. What happens when you try to compile and run the following code? public class Q15 { static String s; public static void main(String[] args) { System.out.println(">>" + s + "<<"); } } A. The code does not compile B. The code compiles, and prints out >><< C. The code compiles, and prints out >>null<<
C
16. What are the legal types for whatsMyType? short s = 10; whatsMyType = !s; A. short B. int C. There are no possible legal types.
C
18. When a negative byte is cast to a long, what are the possible values of the result? A. Positive B. Zero C. Negative
C
18. Which of the following are legal? A. char c = 0x1234; B. char c = \u1234; C. char c = '\u1234';
C
19. Consider the following code: 1. StringBuffer sbuf = new StringBuffer(); 2. sbuf = null; 3. System.gc(); Choose all true statements: A. After line 2 executes, the StringBuffer object is garbage collected. B. After line 3 executes, the StringBuffer object is garbage collected. C. After line 2 executes, the StringBuffer object is eligible for garbage collection. D. After line 3 executes, the StringBuffer object is eligible for garbage collection
C
28. Which of the following statements accurately describes how variables are passed to methods? A. Arguments are always passed by value. B. Arguments are always passed by reference. C. Arguments that are primitive type are passed by value. D. Arguments that are passed with the & operator are passed by reference.
C
3. Which of the following are legal loop constructions? (Choose all that apply.) A. while (int i<7) { i++; System.out.println("i is " + i); } B. int i = 3; while (i) { System.out.println("i is " + i); } C. int j = 0; for (int k=0, j+k != 10; j++,k++) { System.out.println("j=" + j + ", k=" + k); } D. int j=0; do { System.out.println("j=" + j++); if (j==3) continue loop; } while (j<10);
C
7. Consider the following application: 1. class Q7 { 2. public static void main(String args[]) { 3. double d = 12.3; 4. Decrementer dec = new Decrementer(); 5. dec.decrement(d); 6. System.out.println(d); 7. } 8. } 9. 10. class Decrementer { 11. public void decrement(double decMe) { 12. decMe = decMe - 1.0; 13. } 14. } What value is printed out at line 6? A. 0.0 B. 1.0 C. 12.3 D. 11.3
C
7. Consider the following code. Which line will not compile? 1. Object ob = new Object(); 2. String[] stringarr = new String[50]; 3. Float floater = new Float(3.14f); 4. ob = stringarr; 5. ob = stringarr[5]; 6. floater = ob; 7. ob = floater; A. Line 4 B. Line 5 C. Line 6 D. Line 7
C
8. What results from attempting to compile and run the following code? 1. public class Conditional { 2. public static void main(String args[]) { 3. int x = 4; 4. System.out.println("value is " + 5. ((x > 4) ? 99.99 : 9)); 6. } 7. } A. The output: value is 99.99 B. The output: value is 9 C. The output: value is 9.0 D. A compiler error at line 5
C
9. This question concerns the following class definition: 1. package abcde; 2. 3. public class Bird { 4. protected static int referenceCount = 0; 5. public Bird() { referenceCount++; } 6. protected void fly() { /* Flap wings, etc. */ } 7. static int getRefCount() { return referenceCount; } 8. } Which statement is true about class Bird and the following class Parrot? 1. package abcde; 2. 3. class Parrot extends abcde.Bird { 4. public void fly() { 5. /* Parrot-specific flight code. */ 6. } 7. public int getRefCount() { 8. return referenceCount; 9. } 10. } A. Compilation of Parrot.java fails at line 4 because method fly() is protected in the superclass, and classes Bird and Parrot are in the same package. B. Compilation of Parrot.java fails at line 4 because method fly() is protected in the superclass and public in the subclass, and methods may not be overridden to be more public. C. Compilation of Parrot.java fails at line 7 because method getRefCount() is static in the superclass, and static methods may not be overridden to be nonstatic. D. Compilation of Parrot.java succeeds, but a runtime exception is thrown if method fly() is ever called on an instance of class Parrot. E. Compilation of Parrot.java succeeds, but a runtime exception is thrown if method getRefCount() is ever called on an instance of class Parrot.
C
13. Suppose interface Inty defines five methods. Suppose class Classy declares that it implements Inty but does not provide implementations for any of the five interface methods. Which is/are true? (Choose 2) A. The class will not compile. B. The class will compile if it is declared public. C. The class will compile if it is declared abstract. D. The class may not be instantiated.
C, D
16. Which of the following are legal? (Choose 2) A. int a = abcd; B. int b = ABCD; C. int c = 0xabcd; D. int d = 0XABCD; E. int e = 0abcd; F. int f = 0ABCD;
C, D
1. Which of the following statements is correct? (Choose one.) A. Only primitives are converted automatically; to change the type of an object reference, you have to do a cast. B. Only object references are converted automatically; to change the type of a primitive, you have to do a cast. C. Arithmetic promotion of object references requires explicit casting. D. Both primitives and object references can be both converted and cast. E. Casting of numeric types may require a runtime check.
D
10. What is the range of values that can be assigned to a variable of type byte? A. Depends on the underlying hardware B. 0 through 28 − 1 C. 0 through 216 − 1 D. −27 through 27 − 1 E. −215 through 215 − 1
D
12. Which of the following may legally appear as the new type (between the parentheses) in a cast operation? A. Abstract classes B. Final classes C. Primitives D. All of the above
D
14. Suppose a method called finallyTest() consists of a try block, followed by a catch block, followed by a finally block. Assuming the JVM doesn't crash and the code does not execute a System.exit() call, under what circumstances will the finally block not begin to execute? A. The try block throws an exception, and the catch block also throws an exception. B. The try block throws an exception that is not handled by the catch block. C. The try block throws an exception, and the catch block calls finallyTest() in a way that causes another exception to be thrown. D. If the JVM doesn't crash and the code does not execute a System.exit() call, the finally block will always execute.
D
15. Which of the following operations might throw an ArithmeticException? A. >> B. >>> C. << D. None of these
D
16. Which of the following operations might throw an ArithmeticException? A. + B. - C. * D. / E. None of these
D
17. What is the return type of the instanceof operator? A. A reference B. A class C. An int D. A boolean
D
17. When a negative long is cast to a byte, what are the possible values of the result? A. Positive B. Zero C. Negative D. All of the above
D
18. Which of the following statements are true? A. A final class must be instantiated. B. A final class must contain at least one final method. C. A final class must contain at least one final data field. D. A final class may not be extended. E. None of the above.
D
19. Which of the following statements are true? A. A final class must be instantiated. B. A final class may only contain final methods. C. A final class may not contain non-final data fields. D. A final class may not be extended. E. None of the above.
D
2. Consider the following code: 1. outer: for (int i = 0; i < 2; i++) { 2. for (int j = 0; j < 3; j++) { 3. if (i == j) { 4. continue outer; 5. } 6. System.out.println("i = " + i + " j = " + j); 7. } 8. } Which lines would be part of the output? (Choose all that apply.) A. i = 0 j = 0 B. i = 0 j = 1 C. i = 0 j = 2 D. i = 1 j = 0 E. i = 1 j = 1 F. i = 1 j = 2
D
20. What does the following code print? public class A { static int x; public static void main(String[] args) { A that1 = new A(); A that2 = new A(); that1.x = 5; that2.x = 1000; x = -1; System.out.println(x); } } A. 0 B. 5 C. 1000 D. -1
D
20. What is -50 >> 1? A. A negative number with very large magnitude. B. A positive number with very large magnitude. C. -100 D. -25 E. 100 F. 25
D
29. How do you change the value that is encapsulated by a wrapper class after you have instan- tiated it? A. Use the setXXX() method defined for the wrapper class. B. Use the parseXXX() method defined for the wrapper class. C. Use the equals() method defined for the wrapper class. D. None of the above.
D
4. If all three top-level elements occur in a source file, they must appear in which order? A. Imports, package declarations, classes/interfaces/enums B. Classes/interfaces/enums, imports, package declarations C. Package declaration must come first; order for imports and class/interfaces/enum definitions is not significant D. Package declaration, imports, class/interface/enum definitions. E. Imports must come first; order for package declarations and class/interface/enum definitions is not significant
D
4. What would be the output from this code fragment? 1. int x = 0, y = 4, z = 5; 2. if (x > 2) { 3. if (y < 5) { 4. System.out.println("message one"); 5. } 6. else { 7. System.out.println("message two"); 8. } 9. } 10. else if (z > 5) { 11. System.out.println("message three"); 12. } 13. else { 14. System.out.println("message four"); 15. } A. message one B. message two C. message three D. message four
D
5. Consider the following class: 1. class Cruncher { 2. void crunch(int i) { 3. System.out.println("int version"); 4. } 5. void crunch(String s) { 6. System.out.println("String version"); 7. } 8. 9. public static void main(String args[]) { 10. Cruncher crun = new Cruncher(); 11. char ch = 'p'; 12. crun.crunch(ch); 13. } 14. } Which of the following statements is true? (Choose one.) A. Line 5 will not compile, because void methods cannot be overridden. B. Line 12 will not compile, because no version of crunch() takes a char argument. C. The code will compile but will throw an exception at line 12. D. The code will compile and produce the following output: int version. E. The code will compile and produce the following output: String version.
D
5. Which statement is true about the following code fragment? 1. int j = 2; 2. switch (j) { 3. case 2: 4. System.out.println("value is two"); 5. case 2 + 1: 6. System.out.println("value is three"); 7. break; 8. default: 9. System.out.println("value is " + j); 10. break; 11. } A. The code is illegal because of the expression at line 5. B. The acceptable types for the variable j, as the argument to the switch() construct, could be any of byte, short, int, or long. C. The output would be the text value is two. D. The output would be the text value is two followed by the text value is three. E. The output would be the text value is two, followed by the text value is three, fol- lowed by the text value is 2.
D
6. Consider the following application: 1. class Q6 { 2. public static void main(String args[]) { 3. Holder h = new Holder(); 4. h.held = 100; 5. h.bump(h); 6. System.out.println(h.held); 7. } 8. } 9. 10. class Holder { 11. public int held; 12. public void bump(Holder theHolder) { 13. theHolder.held++; } 14. } 15. } What value is printed out at line 6? A. 0 B. 1 C. 100 D. 101
D
6. Which of the following statements is true? (Choose one.) A. Object references can be converted in assignments but not in method calls. B. Object references can be converted in method calls but not in assignments. C. Object references can be converted in both method calls and assignments, but the rules governing these conversions are very different. D. Object references can be converted in both method calls and assignments, and the rules governing these conversions are identical. E. Object references can never be converted.
D
7. Given the following code, and making no other changes, which combination of access modifiers (public, protected, or private) can legally be placed before aMethod() on line 3 and be placed before aMethod() on line 8? 1. class SuperDuper 2. { 3. void aMethod() { } 4. } 5. 6. class Sub extends SuperDuper 7. { 8. void aMethod() { } 9. } A. line 3: public; line 8: private B. line 3: protected; line 8: private C. line 3: default; line 8: private D. line 3: private; line 8: protected E. line 3: public; line 8: protected
D
8. Consider the following code: 1. Dog rover, fido; 2. Animal anim; 3. 4. rover = new Dog(); 5. anim = rover; 6. fido = (Dog)anim; Which of the following statements is true? (Choose one.) A. Line 5 will not compile. B. Line 6 will not compile. C. The code will compile but will throw an exception at line 6. D. The code will compile and run. E. The code will compile and run, but the cast in line 6 is not required and can be eliminated.
D
8. Which modifier or modifiers should be used to denote a variable that should not be written out as part of its class's persistent state? (Choose the shortest possible answer.) A. private B. protected C. private protected D. transient E. volatile
D
9. What is the range of values that can be assigned to a variable of type short? A. Depends on the underlying hardware B. 0 through 216 − 1 C. 0 through 232 − 1 D. −215 through 215 − 1 E. −231 through 231 − 1
D
11. Which of the following may legally appear as the new type (between the parentheses) in a cast operation? A. Classes B. Interfaces C. Arrays of classes D. Arrays of interfaces E. All of the above
E
4. In the following code, what are the possible types for variable result? (Choose the most complete true answer.) 1. byte b = 11; 2. short s = 13; 3. result = b * ++s; A. byte, short, int, long, float, double B. boolean, byte, short, char, int, long, float, double C. byte, short, char, int, long, float, double D. byte, short, char E. int, long, float, double
E
4. Which of the following statements is true? A. Transient methods may not be overridden. B. Transient methods must be overridden. C. Transient classes may not be serialized. D. Transient variables must be static. E. Transient variables are not serialized.
E
5. Which statement is true about this application? 1. class StaticStuff 2 { 3. static int x = 10; 4. 5. static { x += 5; } 6. 7. public static void main(String args[]) 8. { 9. System.out.println("x = " + x); 10. } 11. 12. static {x /= 5; } 13. } A. Lines 5 and 12 will not compile because the method names and return types are missing. B. Line 12 will not compile because you can only have one static initializer. C. The code compiles and execution produces the output x = 10. D. The code compiles and execution produces the output x = 15. E. The code compiles and execution produces the output x = 3.
E
6. Which statement is true about this code? 1. class HasStatic 2. { 3. private static int x = 100; 4. 5. public static void main(String args[]) 6. { 7. HasStatic hs1 = new HasStatic(); 8. hs1.x++; 9. HasStatic hs2 = new HasStatic(); 10. hs2.x++; 11. hs1 = new HasStatic(); 12. hs1.x++; 13. HasStatic.x++; 14. System.out.println("x = " + x); 15. } 16. } A. Line 8 will not compile because it is a static reference to a private variable. B. Line 13 will not compile because it is a static reference to a private variable. C. The program compiles and the output is x = 102. D. The program compiles and the output is x = 103. E. The program compiles and the output is x = 104.
E
8. Consider the following class hierarchy and code fragment: 1. try { 2. // assume s is previously defined 3. URL u = new URL(s); 4. // in is an ObjectInputStream 5. Object o = in.readObject(); 6. System.out.println("Success"); 7. } 8. catch (MalformedURLException e) { 9. System.out.println("Bad URL"); 10. } 11. catch (StreamCorruptedException e) { 12. System.out.println("Bad file contents"); 13. } 14. catch (Exception e) { 15. System.out.println("General exception"); 16. } 17. finally { 18. System.out.println("Doing finally part"); 19. } 20. System.out.println("Carrying on"); What lines are output if the method at line 5 throws an OutOfMemoryError? (Choose all that apply.) A. Success B. Bad URL C. Bad file contents D. General exception E. Doing finally part F. Carrying on
E
9. Consider the following code: 1. Cat sunflower; 2. Washer wawa; 3. SwampThing pogo; 4. 5. sunflower = new Cat(); 6. wawa = sunflower; 7. pogo = (SwampThing)wawa; Which of the following statements is true? (Choose one.) A. Line 6 will not compile; an explicit cast is required to convert a Cat to a Washer. B. Line 7 will not compile, because you cannot cast an interface to a class. C. The code will compile and run, but the cast in line 7 is not required and can be eliminated. D. The code will compile but will throw an exception at line 7, because runtime conversion from an interface to a class is not permitted. E. The code will compile but will throw an exception at line 7, because the runtime class of wawa cannot be converted to type SwampThing.
E
12. Which of the following statements are true? A. An abstract class may be instantiated. B. An abstract class must contain at least one abstract method. C. An abstract class must contain at least one abstract data field. D. An abstract class must be overridden. E. An abstract class must declare that it implements an interface. F. None of the above.
F
15. Which of the following are legal loop definitions? (Choose all that apply.) A. while (int a = 0) { /* whatever */ } B. while (int a == 0) { /* whatever */ } C. do { /* whatever */ } while (int a = 0) D. do { /* whatever */ } while (int a == 0) E. for (int a==0; a<100; a++) { /* whatever */ } F. None of them are legal.
F
2. Choose the valid identifiers from those listed here. (Choose all that apply.) A. BigOlLongStringWithMeaninglessName B. $int C. bytes D. $1 E. finalist F. All of the other choice
F
