成员变量，静态方法看左边；非静态方法：编译看左边，运行看右边。

 

1 public class BoundDemo { 2     public static void main(String[] args) { 3         A a=new B(); 4         System.err.println(a.age); 5         System.err.println(a.num); 6         a.abc(); 7         a.abcd(); 8     } 9     10 }11 12 class A13 {14     public int age=100;15     public static int num=100;16     public static void abc()17     {18         System.err.println("100......");19     }20     public void abcd()21     {22         System.err.println("100.......");23     }24 }25 26 class B extends A27 {28     public int age=1000;29     public static int num=1000;30     public static void abc()31     {32         System.err.println("1000......");33     }34     public void abcd()35     {36         System.err.println("1000.......");37     }38 }