藍冰飛寒

instanceof　　instanceof是Java的一個二元操作符，和==，>，<是同一類東西。由于它是由字母組成的，所以也是Java的保留關鍵字。它的作用是測試它左邊的對象是否是它右邊的類的實例，返回boolean類型的數據。舉個例子：
　　String s = "I AM an Object!";
　　boolean isObject = s instanceof Object;

給出個例題： class Animal{
    public String name ;
    public Animal(String name){
        this.name=name;
    }
}
class Dog extends Animal{
    public String furcolor;
    public Dog(String n,String furcolor){
            super(n);this.furcolor=furcolor;
    }
}
class Cat extends Animal{
    public String eyecolor;
    public Cat(String n,String eyecolor){
        super(n);this.eyecolor=eyecolor;
    }
}



public class Test{
      public static void main(String args[]){
          Animal a= new Animal("name");
          Cat cat=new Cat("xiaohua","blue");
          Dog dog=new Dog("xiaohuang","Yellow");
          
          System.out.println(a instanceof Animal);
          System.out.println(cat instanceof Animal);
          System.out.println(dog instanceof Animal);
          System.out.println(a instanceof Cat);
            a=new Dog("BigYellow","Yellow");
            System.out.println(a.name);
            Dog b=(Dog)a;
            System.out.println(b.furcolor);
      }
}
Tags - java
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