Java作业8及答案.docVIP

一、 1. class Something final int i; public void doSomething System.out.println i + i ; 7. interface Playable void play ; interface Bounceable void play ; interface Rollable extends Playable, Bounceable 牋?Ball ball new Ball PingPang ; class Ball implements Rollable private String name; public String getName return name; public Ball String name this.name name; public void play ball new Ball Football ; System.out.println ball.getName ; 二、 class MyThread extends Thread public void run System.out.println MyThread: run ; public void start System.out.println MyThread: start ; class MyRunnable implements Runnable public void run System.out.println MyRunnable: run ; public void start System.out.println MyRunnable: start ; public class MyTest public static void main String args[] MyThread myThread new MyThread ; MyRunnable myRunnable new MyRunnable ; Thread thread new Thread myRunnable ; myThread.start ; thread.start ; A.打印MyThread: start 后面跟 MyRunnable: run B.打印MyThread: run 后面跟MyRunnable: start C.打印MyThread: start 后面跟MyRunnable: start D.打印MyThread: run 后面跟MyRunnable: run 2. // 文件名：SuperclassX.java package packageX; public class SuperclassX protected void superclassMethodX int superclassVarX; //文件名：SubclassY.java 1.package packageX.packageY; 2. 3.public class SubclassY extends SuperclassX 4. 5. SuperclassX objX new SubclassY ; 6. SubclassY objY new SubclassY ; 7. void subclassMethodY 8. 9. objY.superclassMethodX ; 10. int i; 11. i objY.superclassVarX; 12. 13. A.第5行编译错 B.第9行编译错 C.第11行意外 D.都不是 3. 程序段如下： 1.class MyClass 2. 3. void myMethod int i System.out.println int version ; 4. void myMethod String s System.out.println String version ; 5. public static void main String args[] 6. 7. MyClass obj new MyClass ; 8. char ch c; 9. obj.myMethod ch ; 10. 11. A.第四行编译出错 B.第九行抛出例外 C.输出结果：int version D.输出结果：String version 4. public class ThrowsDemo static void throwMethod System.