Java之動態綁定（多態）

動態綁定是指在執行期間判斷所引用對象的實際類型，根據其實際的類型調用相應的方法

動態綁定的三個條件：

1.要有繼承

2.要有方法重寫

3.要有父類引用指向子類對象

class Animal {
	private String name;
	Animal(String name) {
		this.name = name;
	}
	
	public void enjoy() {
		System.out.println("animalshout...");
	}
	
}

class Cat extends Animal {
	private String eyesColor;
	Cat(String n,String c) {
		super(n);
		eyesColor = c;
	}
	
	public void enjoy() {
		System.out.println("catshoult...");
	}
}

class Dog extends Animal {
	private String furColor;
	Dog(String n,String c) {
		super(n);
		furColor = c;
	}
	public void enjoy() {
		System.out.println("dogshoult...");
	}
}


class Lady {
	private String name;
	private Animal pet;
	Lady(String name, Animal pet) {
		this.name = name;
		this.pet = pet;
	}
	public void myPetEnjoy() {
		pet.enjoy();
	}
}

public class TestTai {
	public static void main(String[] args) {
		Cat c = new Cat("catname", "blue");
		Dog d = new Dog("d ogname", "black");
		
		Lady l1 = new Lady("l1", c);
		Lady l2 = new Lady("l2", d);
		
		l1.myPetEnjoy();
		l2.myPetEnjoy();
		
		
	}
}

l1調用的是pet的方法，本來是animal引用，但是實際上是用的是cat對象，那就綁定到cat對象重寫的方法