Object x = t.findLarger(123, “456”);
int x = t.findLarger(123, new Double(456));
int x = t.findLarger(123, new Integer(456));
int x = (int) t.findLarger(new Double(123), new Double(456));
第1题:
有如下类定义: class Test { private int x; public int y; public void setX (int m) {x=m;} public int getX( ) {return x;} }现用Test t=new Text();生成一个对象t,则如下语句中,错误的是( )。
A.t.x=10;
B.t.y=10;
C.t. setX(10);
D.int m=t.getX( );
第2题:
在下列源代码文件Test.java中, ( )是正确的类定义。
A.public class test{
B.public class Test{ public int x=0;public int x=0; public test (intx) public Test (int x){ {this.x=x; this.x=x;} }} }
C.public class Test extends T1,T2{
D.protected class Test extends T2{ public int=0;public int x=0; public Test(int x){Public Test (int x){ this.x=x;this.x=x: }} }}
第3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4题:
1. public class Exception Test { 2. class TestException extends Exception {} 3. public void runTest() throws TestException {} 4. public void test() /* Point X */ { 5. runTest(); 6. } 7. } At Point X on line 4, which code is necessary to make the code compile?()
第5题:
1. public class Test { 2. public
第6题:
1. class MyThread implements Runnable { 2. public void run() { 3. System.out.print("go "); 4. } 5. 6. public static void main(String [] args) { 7. // insert code here 8. t.start(); 9. } 10. } 和如下四句: Thread t = new MyThread(); MyThread t = new MyThread(); Thread t = new Thread(new Thread()); Thread t = new Thread(new MyThread()); 分别插入到第5行,有几个可以通过编译?()
第7题:
1. import java.io.*; 2. public class Foo implements Serializable { 3. public int x, y; 4. public Foo( int x, int y) { this.x = x; this.y = y; } 5. 6. private void writeObject( ObjectOutputStream s) 7. throws IOException { 8. s.writeInt(x); s.writeInt(y) 9. } 10. 11. private void readObject( ObjectInputStream s) 12. throws IOException, ClassNotFoundException { 13. 14. // insert code here 15. 16. } 17. } Which code, inserted at line 14, will allow this class to correctly serialize and deserialize?()
第8题:
1. class Bar { } 1. class Test { 2. Bar doBar() { 3. Bar b = new Bar(); 4. return b; 5. } 6. public static void main (String args[]) { 7. Test t = new Test(); 8. Bar newBar = t.doBar(); 9. System.out.println(“newBar”); 10. newBar = new Bar(); 11. System.out.println(“finishing”); 12. } 13. } At what point is the Bar object, created on line 3, eligible for garbage collection?()
第9题:
int doStuff() { return 42; }
int doStuff(int x) { return 42; }
Foo doStuff(int x) { return new Foo(); }
SuperFoo doStuff(int x) { return new Foo(); }
第10题:
No code is necessary.
throws Exception
catch ( Exception e )
throws RuntimeException
catch ( TestException e)
第11题:
public int blipvert(int x) { return 0; }
private int blipvert(int x) { return 0; }
private int blipvert(long x) { return 0; }
protected long blipvert(int x, int y) { return 0; }
protected int blipvert(long x) { return 0; }
protected long blipvert(long x) { return 0; }
protected long blipvert(int x) { return 0; }
第12题:
float getVar() { return x; }
public float getVar() { return x; }
public double getVar() { return x; }
protected float getVar() { return x; }
public float getVar(float f) { return f; }
第13题:
执行下面程序,显示的结果为( )。 public class Test { public static void main (String args[]) { Test t=newTest(); System.out.println (Loverload ("2","3")); } int overload (intx,int y) {return x+y;} String overload (String x,Stnng y){return x+y;} }
A.2
B.3
C.5
D.23
第14题:
在下列源代码文件Test.java中,哪个选项是正确的类定义?
A.public class test{ public int x=0; public test(int x ) { this.x=x; } }
B.public class Test { public int x=0; public Test(int x ) { this.x=x; } }
C.public class Test extends T1 T2 { public int x=0; public Test(int x){ this.x=x; } }
D.protected class Test extends T2 { public int x=0; public Test(int x) { this.x=x; } }
第15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16题:
public class X { public X aMethod() { return this;} } public class Y extends X { } Which two methods can be added to the definition of class Y?()
第17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18题:
1. public class Test { 2. int x= 12; 3. public void method(int x) { 4. x+=x; 5. System.out.println(x); 6. } 7. } Given: 34. Test t = new Test(); 35. t.method(5); What is the output from line 5 of the Test class?()
第19题:
1. public class test ( 2. public static void main(string args[]) { 3. int 1= 0; 4. while (i) { 5. if (i==4) { 6. break; 7. } 8. ++i; 9. } 10. 11. } 12. ) What is the value of i at line 10?()
第20题:
1. public class Blip { 2. protected int blipvert(int x) { return 0; } 3. } 4. class Vert extends Blip { 5. // insert code here 6. } Which five methods, inserted independently at line 5, will compile?()
第21题:
Object x = t.findLarger(123, “456”);
int x = t.findLarger(123, new Double(456));
int x = t.findLarger(123, new Integer(456));
int x = (int) t.findLarger(new Double(123), new Double(456));
第22题:
5
10
12
17
24
第23题:
public void aMethod() {}
private void aMethod() {}
public void aMethod(String s) {}
private Y aMethod() { return null; }
public X aMethod() { return new Y(); }
第24题:
After line 8.
After line 10.
After line 4, when doBar() completes.
After line 11, when main() completes.