Instanceof and isinstance in Java

public class Main {

public static void main(String[] args) {

C t1=new C();

D t2=new D();

//obj  instanceof  class:这个对象是不是这种类型.

//测试1:一个对象是本身类的一个对象

System.out.println(t1 instanceof C);

//测试2:一个对象是本身类父类(父类的父类)和接口的一个对象

System.out.println(t1 instanceof A);

System.out.println(t2 instanceof D);

//测试3:所有对象都是object

System.out.println(t1 instanceof Object);

System.out.println(t2 instanceof Object);

//测试4:凡是null相关的都是false

System.out.println(null instanceof Object);

System.out.println(null instanceof B);

    //class.<a href="https://www.jb51.cc/tag/isinstance/" target="_blank" class="keywords">isinstance</a>(obj):这个对象能不能被转化为这个类
    //测试1:<a href="https://www.jb51.cc/tag/yige/" target="_blank" class="keywords">一个</a>对象是本身类的<a href="https://www.jb51.cc/tag/yige/" target="_blank" class="keywords">一个</a>实例
    Sy<a href="https://www.jb51.cc/tag/stem/" target="_blank" class="keywords">stem</a>.out.println(C.class.<a href="https://www.jb51.cc/tag/isinstance/" target="_blank" class="keywords">isinstance</a>(t1));
    //测试2:<a href="https://www.jb51.cc/tag/yige/" target="_blank" class="keywords">一个</a>对象能被转化为本身类所继承的类(<a href="https://www.jb51.cc/tag/fulei/" target="_blank" class="keywords">父类</a>的<a href="https://www.jb51.cc/tag/fulei/" target="_blank" class="keywords">父类</a>)和实现的接口(接口的父接口)强转
    Sy<a href="https://www.jb51.cc/tag/stem/" target="_blank" class="keywords">stem</a>.out.println(A.class.<a href="https://www.jb51.cc/tag/isinstance/" target="_blank" class="keywords">isinstance</a>(t1));
    Sy<a href="https://www.jb51.cc/tag/stem/" target="_blank" class="keywords">stem</a>.out.println(B.class.<a href="https://www.jb51.cc/tag/isinstance/" target="_blank" class="keywords">isinstance</a>(t2));
    //测试3:所有对象都能被Object强转
    Sy<a href="https://www.jb51.cc/tag/stem/" target="_blank" class="keywords">stem</a>.out.println(Object.class.<a href="https://www.jb51.cc/tag/isinstance/" target="_blank" class="keywords">isinstance</a>(t1));
    Sy<a href="https://www.jb51.cc/tag/stem/" target="_blank" class="keywords">stem</a>.out.println(Object.class.<a href="https://www.jb51.cc/tag/isinstance/" target="_blank" class="keywords">isinstance</a>(t2));
    //测试4:凡是和null相关的都是false
    Sy<a href="https://www.jb51.cc/tag/stem/" target="_blank" class="keywords">stem</a>.out.println(Object.class.<a href="https://www.jb51.cc/tag/isinstance/" target="_blank" class="keywords">isinstance</a>(null));
    Sy<a href="https://www.jb51.cc/tag/stem/" target="_blank" class="keywords">stem</a>.out.println(D.class.<a href="https://www.jb51.cc/tag/isinstance/" target="_blank" class="keywords">isinstance</a>(null));
}



    }