Question

题目级别：助理工程师【适中】

下列代码正确的是哪项？( )

备选答案

 public class Session implements Runnable, Cloneable {
    public void run();
    public Object clone();
}

 public class Session extends Runnable, Cloneable {
    public void run() {/*do something*/}
    public Object clone() {/*make a copy*/}
}

 public abstract class Session implements Runnable, Cloneable {
    public void run() {/*do something*/}
    public Object clone() {/*make a copy*/}
}

 public class Session implements Runnable, implements Cloneable {
    public void run() {/*do something*/}
    public Object clone() {/*make a copy*/}
}

解题分析

Java不支持类的多继承
方法头只能写在接口中
extends和implements在一个声明中值出现一次