instanceof

Posted 2020-06-19 storm47

public static void main(String ages[]){
        //向上转型
        
        Object obj=new jicheng();
        
        
        //关键字 instanceof
        //判断某个对象是否是某个类的实例，返回boolean
        
        if(obj instanceof jicheng){
            
            System.out.println("obj是jicheng的实例");
        }
        
        
        fulei f=new fulei("");
        
        //f是否是jicheng(子类)的实例
        if(f instanceof jicheng){
            
            System.out.println("f是jicheng的实例");
        }
        else{System.out.println("f不是jicheng的实例");}
        
        //obj是不是fulei(父类)的实例
         if(obj instanceof fulei){
            
            System.out.println("obj是fulei的实例");
        }
        else{System.out.println("obj不是fulei的实例");}
        
        
        //向下转型
        
        jicheng s=(jicheng)obj;
        
        s.work();
    }