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第1题:
1. public class Target { 2. private int i = 0; 3. public int addOne() { 4. return ++i; 5. } 6. } And: 1. public class Client { 2. public static void main(String[] args) { 3. System.out.println(new Target().addOne()); 4. } 5. } Which change can you make to Target without affecting Client?()
第2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3题:
1. public class ReturnIt { 2. return Type methodA(byte x, double y) { 3. return (long)x / y * 2; 4. } 5. } What is the narrowest valid returnType for methodA in line2?()
第4题:
1. class SuperFoo { 2. SuperFoo doStuff(int x) { 3. return new SuperFoo(); 4. } 5. } 6. 7. class Foo extends SuperFoo { 8. //insert code here 9. } 下面哪三项分别插入到第8行,可以编译?()
第5题:
1. public class Test { 2. public
第6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7题:
现有: 1. class Synapse { 2. protected int gap() { return 7; } 3. } 4. 5. class Creb extends Synapse { 6. // insert code here 7. } 分别插入到第 6 行,哪三行可以编译?()
第8题:
1. class BaseClass { 2. private float x = 1.of; 3. protected float getVar() { return x; } 4. } 5. class SubClass extends BaseClass { 6. private float x = 2.Of; 7. // insert code here 8. } Which two are valid examples of method overriding when inserted at line 7?()
第9题:
1. public class returnIt ( 2. returnType methodA(byte x, double y) ( 3. return (short) x/y * 2; 4. ) 5. ) What is the valid returnType for methodA in line 2?()
第10题:
1. public class ReturnIt { 2. return Type methodA(byte x, double y) { 3. return (short)x / y * 2; 4. } 5. } What is the narrowest valid returnType for methodA in line2?()