package day09;
/*
* 成员变量:
* 编译看左边(父类),运行看左边(父类)
* */
class Demo_PolyMorphic {
public static void main(String[]args){
Father f=new Son();
System.out.println(f.num);
Son s=new Son();
System.out.println(s.num);
}
}
class Father{
int num=10;
}
class Son extends Father{
int num=20;
}
运行结果:
10
20