A: public class X implements Runnable{ public void run(){......} }
B: public class X implements Thread{ public void run(){......} }
C: public class X implements Thread{ public int run(){......} }
D: public class X extends Runnable{ public void run(){......} }
举一反三
- 下列哪个方法可用于创建一个可运行的类（） A: public class X implements Runnable{public void run() {……}} B: public class X extends Thread{public void run() {……}} C: public class X extends Thread{public int run() {……}} D: public class X implements Runnable{protected void run() {……}}
- 下列关于Test类的定义代码中，正确的是______。 A: class Test implements Runnable { public void run() {} public void someMethod() {} } B: class Test implements Runnable { public void run(); } C: class Test implements Runnable { public void someMethod(); } D: class Test implements Runnable { public void someMethod() {} }
- class X implements Runnable{public static void main(String args[]){/* Missing code? */}public void run() {}}哪一行代码适合启动线程？ A: Thread t = new Thread(X); B: Thread t = new Thread(X);t.start(); C: X run = new X();Thread t = new Thread(run);t.start(); D: Thread t = new Thread();x.run();
- Given: 1. public class Foo implements Runnable { 2. public void run (Thread t) { 3. System.out.println("Running."); 4. } 5. public static void main (String[] args) { 6. new Thread (new Foo()).start(); 7. } 8. } What is the result?
- interface A{ void x(); } class B implements A{ public void x(){} public void y(){} } class C extends B{ public void x(){System.out.println("C");} } public class Test{ public static void main(String args[]){ B b=new B(); B c=new C(); b.x(); c.y(); } } A: 程序运行错误 B: 程序没有输出结果 C: 程序输出C。 D: class B implements A 编译错误 E: c.y();编译错误
内容
- 0
给定代码如下: public abstract interface Frobnicate { public void twiddle(String s); } 以下哪个类是正确的?(). A: public abstract class Frob implements Frobnicate { public abstract void twiddle(String s) { } } B: public abstract class Frob implements Frobnicate { } C: public class Frob extends Frobnicate { public void twiddle(Integer i) { } } D: public class Frob implements Frobnicate { public void twiddle(Integer i) { } }
- 1
已知有如下定义：package cn.edu.ncu.chenyi;public interface Runnable{public void run();}package cn.edu.ncu.chenyi;public abstract class Animal implements Runnable{public void run();}关于上述两个代码说法正确的是？ A: Animal编译失败，因为Animal类实现接口，不能定义为抽象类 B: Animal编译失败，因为Animal类实现接口Runnable,方法run的方法不是抽象方法，方法体不能为空； C: Animal编译失败，需要在方法run中增加修饰符abstract才能修改正确，形如：package cn.edu.ncu.chenyi;public abstract class Animal implements Runnable{ public abstract void run();} D: Animal编译成功，代码正确； E: 以上说法均不正确
- 2
下列程序运行结果是( ) public class Demo { public static void main(String[] args) { Demo demo = new Demo(); demo.show(new Car() { public void run() { System.out.println("demo run"); } }); } public void show(Car c) { c.run(); } }abstract class Car { public void run() { System.out.println("car run..."); } }
- 3
现有 public class Parent{ public void change (int x){ } } public class Child extends Parent{ ／／覆盖父类change方法 }下列哪个声明是正确的覆盖了父类的change方法？ A: protected void change (int x){} B: public void change(int x, int y){} C: public void change (int x){} D: public void change (String s){}
- 4
public class Parent{ public void change（int x）{} } public class Child extends Parent{ //覆盖父类change方法 } 下列哪个声明是正确的覆盖了父类的change方法？（） A: protected void change（int x）{} B: public void change（int x， int y）{} C: public void change（String s）{} D: public void change（int x）{}