java 抽象类与接口

抽象类与抽象方法

//抽象类  意义：单纯被继承
[权限修饰符]abstract class 类名{

// 抽象方法 继承抽象类的所有子类 都要重写抽象类中的抽象方法
[权限修饰符] abstract 方法返回值类型 方法名(参数列表);  //无方法体 

} 

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public class GoShopping {
    public static void main(String[] args) {
        Shopping tb = new TBShopping();
        tb.market = "淘宝";
        tb.goods = "衣服";
        System.out.println("在"+tb.market+tb.shop()+tb.goods);

        Shopping xx = new XXShopping();
        xx.market = "实体店";
        xx.goods = "鞋子";
        System.out.println("在"+xx.market+xx.shop()+xx.goods);

    }
}

// 抽象类 买东西
abstract class Shopping {
    public String market;  //购买地
    public String goods; //商品

    public abstract String shop(); //抽象方法 购买行为

}


class TBShopping extends Shopping{   //网购类
     public  String shop(){
         return "网购";
    }
}

class XXShopping extends Shopping{    //线下购类
    public  String shop(){
        return "线下买";
    }
}
            /*在淘宝网购衣服
            在实体店线下买鞋子*/

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public class GoShopping {
    public static void main(String[] args) {
       Shopping tb = new TBShopping();
tb.market = "淘宝";
tb.goods = "衣服";
System.out.println("在"+tb.market+tb.shop()+tb.goods);

Shopping xx = new XXShopping();
xx.market = "实体店";
xx.goods = "鞋子";
System.out.println("在"+xx.market+xx.shop()+xx.goods);

}
}

// 抽象类 买东西
abstract class Shopping {
    public String market;  //购买地
public String goods; //商品

public abstract String shop(); //抽象方法 购买行为

}


class TBShopping extends Shopping{   //网购类
public  String shop(){
      return "网购";
}
}

class XXShopping extends Shopping{    //线下购类
public  String shop(){
      return "线下买";
}
}
         /*在淘宝网购衣服
         在实体店线下买鞋子*/

接口