Compilation will succeed if a extends b.
Compilation will succeed if b extends a.
Compilation will always fail because of an error in line 7.
Compilation will always fail because of an error in line 8.
第1题:
1. public interface A { 2. public void doSomething(String thing); 3. } 1. public class AImpl implements A { 2. public void doSomething(String msg) { } 3. } 1. public class B { 2. public A doit() { 3. // more code here 4. } 5. 6. public String execute() { 7. // more code here 8. } 9. } 1. public class C extends B { 2. public AImpl doit() { 3. // more code here 4. } 5. 6. public Object execute() { 7. // more code here 8. } 9. } Which statement is true about the classes and interfaces in the exhibit?()
第2题:
1. class A { 2. public byte getNumber () { 3. return 1; 4. } 5. } 6. 7. class B extends A { 8. public short getNumber() { 9. return 2; 10. } 11. 12. public static void main (String args[]) { 13. B b = new B (); 14. System.out.printIn(b.getNumber()) 15. } 16. } What is the result?()
第3题:
1. package foo; 2. 3. import java.util.Vector; 4. 5. private class MyVector extends Vector { 6. int i = 1; 7. public MyVector() { 8. i = 2; 9. } 10. } 11. 12. public class MyNewVector extends MyVector { 13. public MyNewVector () { 14. i = 4; 15. } 16. public static void main (String args []) { 17. MyVector v = new MyNewVector(); 18. } 19. } The file MyNewVector.java is shown in the exhibit. What is the result?()
第4题:
ClassOne.java: 1. package com.abe.pkg1; 2. public class ClassOne { 3. private char var = ‘a’; 4. char getVar() { return var; } 5. } ClassTest.java: 1. package com.abe.pkg2; 2. import com.abc.pkg1.ClassOne; 3. public class ClassTest extends ClassOne { 4. public static void main(String[] args) { 5. char a = new ClassOne().getVar();6. char b = new ClassTest().getVar(); 7. } 8. } What is the result?()
第5题:
1. class A { 3. public String to String() { 4. return “4”; 5. } 6. } 7. class B extends A { 8. public String toString() { 9. return super.toString() + “3”; 10. } 11. } 12. public class Test { 13. public static void main (String[] args) { 14. System.out.printIn(new B()); 15. } 16. } What is the result( )?
第6题:
1. class Exc0 extends Exception { } 2. class Exc1 extends Exc0 { } 3. public class Test { 4. public static void main(String args[]) { 5. try { 6. throw new Exc1(); 7. } catch (Exc0 e0) { 8. System.out.println(“Ex0 caught”); 9. } catch (Exception e) { 10. System.out.println(“exception caught”); 11. } 12. } 13. } What is the result?()
第7题:
Compilation will fail.
Compilation succeeds and no exceptions are thrown.
Compilation succeeds but an exception is thrown at line 5 in ClassTest.java.
Compilation succeeds but an exception is thrown at line 6 in ClassTest.java.
第8题:
Compilation succeeds and 1 is printed.
Compilation succeeds and 2 is printed.
An error at line 8 causes compilation to fail.
An error at line 14 causes compilation to fail.
Compilation succeeds but an exception is thrown at line 14.
第9题:
Compilation succeeds and l is printed.
Compilation succeeds and 2 printed.
An error at line 8 cause compilation to fail.
An error at line 14 cause complication to fail.
Complication succeeds but an exception is thrown at line 14.
第10题:
Compilation will succeed.
Compilation will fail at line 5.
Compilation will fail at line 6.
Compilation will fail at line 14.
Compilation will fail at line 17.
第11题:
Compilation succeeds and 1 is printed.
Compilation succeeds and 2 is printed.
An error at line 8 causes compilation to fail.
An error at line 13 causes compilation to fail.
An error at line 14 causes compilation to fail.
第12题:
Compilation succeeds and 4 is printed.
Compilation succeeds and 43 is printed.
An error on line 9 causes compilation to fail.
An error on line 14 causes compilation to fail.
Compilation succeeds but an exception is thrown at line 9.
第13题:
1. public class A { 2. public void doit() { 3. } 4. public String doit() { 5. return “a”; 6. } 7. public double doit(int x) { 8. return 1.0; 9. } 10.} What is the result?()
第14题:
1. class SuperClass { 2. public a geta() { 3. return new a(); 4. } 5. } 6. class SubClass extends SuperClass { 7. public b geta() { 8. return new b(); 9. } 10. } Which is true?()
第15题:
1. class A { 2. public String toString () { 3. return “4”; 4. } 5. } 6. class B extends A { 7. public String toString () { 8. return super.toString() + “3”; 9. } 10. } 11. public class Test { 12. public static void main(String[]args) { 13. System.out.printIn(new B()); 14. } 15. } What is the result?()
第16题:
ClassOne.java 1. package com.abc.pkg1; 2. public class ClassOne { 3. private char var = ‘a’; 4. char getVar() {return var;} 5. } ClassTest.java 1. package com.abc.pkg2; 2. import com.abc.pkg1.ClassOne; 3. public class ClassTest extends ClassOne { 4. public static void main(String[]args) { 5. char a = new ClassOne().getVar(); 6. char b = new ClassTest().getVar(); 7. } 8. } What is the result?()
第17题:
1. class A { 2. public byte file Number ( ) { 3. return l; 4. } 5. } 6. 7. Class B extends A { 8. public short getNumber( ) { 9. return 2; 10. } 11. 12. public short getNumber( ) { 13. B b = new B( ); 14. System.out.printIn(b.getNumber( )); 15. } 16. } What is the result()?
第18题:
Compilation will succeed for all classes and interfaces.
Compilation of class C will fail because of an error in line 2.
Compilation of class C will fail because of an error in line 6.
Compilation of class AImpl will fail because of an error in line 2.
第19题:
Compilation succeeds and 4 is printed.
Compilation succeeds and 43 is printed.
An error on line 9 causes compilation to fail.
An error on line 14 causes compilation to fail.
Compilation succeeds but an exception is thrown at line 9.
第20题:
public void getNum(){}
public void getNum(double d){}
public float getNum() { return 4.0f; }
public double getNum(float d) { return 4.0d; }
第21题:
Compilation fails.
Compilation succeeds and no exceptions are thrown.
An exception is thrown at line 5 in ClassTest.java.
An exception is thrown at line 6 in ClassTest.java.
第22题:
Compilation succeeds and 4 is printed.
Compilation …………… is printed.
An error on line 9 cause compilation to fail.
An error on line 14 cause compilation to fail.
Compilation succeeds but an exception is thrown at line 9.
第23题:
An exception is thrown at runtime.
Compilation fails because of an error in line 7.
Compilation fails because of an error in line 4.
Compilation succeeds and no runtime errors with class A occur.