Java 面向对象 之 多态实例2

/**
	题目: 孩子吃 水果(苹果,葡萄,芒果,菠萝)

	思路:
		1. 抽象出类 : 孩子(Baby), 水果(Fruit)(苹果(Apple),葡萄(Grape),芒果(Mango))
		2. 找出类的关系: 水果 -> 孩子   (苹果,葡萄,芒果) 是 水果的分类
		3. 找出属性: 孩子(姓名,水果引用)  
		4. 找出方法: 孩子吃(eat)水果

	子类->父类的转换 作用 :解耦 也就是降低类与类之间的耦合度 提供可扩展性
*/
public class Polymorphism3 {
	
	public static void main(String[] args) {
		//实例化一个Baby
		Baby baby = new Baby("李明");

		//实例化一个苹果 和 一个葡萄
		Apple apple = new Apple("红富士");
		Grape grape = new Grape("黑葡萄");
		Mango mango = new Mango("大芒果");
		PineApple pineApple = new PineApple("菠萝");

		//李明吃苹果
		baby.eat(apple);
		System.out.println(baby.getName() + " 吃了 " + baby.getFruit().getName());
		baby.eat(grape);
		System.out.println(baby.getName() + " 吃了 " + baby.getFruit().getName());
		baby.eat(mango);
		System.out.println(baby.getName() + " 吃了 " + baby.getFruit().getName());
		baby.eat(pineApple);
		System.out.println(baby.getName() + " 吃了 " + baby.getFruit().getName());

	}
}

class Baby {
	private Fruit fruit;
	private String name;

	public Baby(String name) {
		this.name = name;
	}

	public String getName() {
		return this.name;
	}

	public Fruit getFruit() {
		return this.fruit;
	}

	//吃水果
	public void eat(Fruit fruit) {
		this.fruit = fruit;
	}

}

class Fruit {
	
	private String name;

	public Fruit(String name) {
		this.name = name;
	}

	public String getName() {
		return this.name;
	}
}

class PineApple extends Fruit {
	
	public PineApple(String name) {
		super(name);
	}
}

class Apple extends Fruit {
	
	public Apple(String name) {
		super(name);
	}
}

class Grape extends Fruit {
	
	public Grape(String name) {
		super(name);
	}
}

class Mango extends Fruit {
	
	public Mango(String name) {
		super(name);
	}
}


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Java 面向对象 之 多态实例2