java抽象类

java abstract class

有时候，我们需要用到抽象类。比如我们想买水果，但是不确定买的是苹果还是香蕉

Sometimes, we want to abstract a class.For example, We want buy some fruits,but we are not sure we buy apple or pear.

我们抽象出一个类叫水果

Now we can abstract a class named Fruit

水果就作为了一个抽象类和一个父亲类

Fruit is a abstract class and it is a father class.

苹果和梨就作为子类

Apples and pears fruit is child class

注意：我们不能获得一个抽象类的对象 new Fruit() 会发生错误。

note: can not get a new abstract class new Fruit() is wrong

abstract father classpublic abstract class Fruit {	public String getColor(String color){		return color;	}	public String getWeight(String weight){		return weight;	}}

child class

public class Apple extends Fruit {
     	public String getColor(String color){
     		System.out.println(‘‘color is ‘‘ + color); 		return color; 	} 	public String getWeight(String weight){
     		System.out.println(‘‘weight is ‘‘ + weight); 		return weight; 	} 	public static void main(String[] args){
     		Fruit f = new Apple(); 		//Fruit f = new Fruit();   can not get a new abstract class  new Fruit() is wrong 		f.getColor(‘‘red‘‘); 	} }

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