java方法多态，变量没有多态

public class Main { 
	
    public static void main(String[] args){
    	Father father = new Father();
    	Son s = new Son();
    	father = s;
    	father.fo();
    	System.out.println(father.i);
    	System.out.println(s.i);
    	s=(Son) father;
    	System.out.println(s.i);
    }
}
class Father{
	int i =1;
	public void fo() {
		System.out.println(i);
	}
}
class Son extends Father{
	int i =2;
	public void fo() {
		System.out.println(i);
	}
	public void foo() {
		System.out.println(i+10);
	}
}

执行的结果为：2   1   2  2

	Father father = new Father();
    	Son s = new Son();
    	father = s;

等同于Father father = new Son（）；由此可见变量是不会显示出多态的