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2017/05/23 java 基础 随笔

1.多态的好处:

    a.提高了代码的维护性(继承保证)

    b.提高了代码的扩展性(由多态保证)

package com.huawei;

public class Demo2 {

	public static void main(String[] args) {
		creatMethod(new Cat());
	}
	public static void creatMethod(Animal a){
		if(a instanceof Cat){
			Cat c=(Cat)a;
			c.catchrat();
		}else if(a instanceof Dog){
			Dog d=(Dog)a;
			d.shout();
		}
	}
}

class Animal{
	public void eat(){
		System.out.println("動物吃");
	}
}
class Cat extends Animal {
	public void eat() {
		System.out.println("貓吃");
	}
	public void catchrat(){
		System.out.println("貓抓老鼠");
	}
}
class Dog extends Animal{
	public void eat() {
		System.out.println("狗吃");
	}
	public void shout () {
		System.out.println("狗叫");
	}
}

 

2017/05/23 java 基础 随笔