java中instanceof用法

java中instanceof用法

废话少说，还是举几个例子：

public interface A{}

public class B implements A{

public static void main(String[] args){

A a=null;

B b=null;

if(a instanceof A){

System.out.println("true 1");

}

else{

System.out.println("false 1");

}

if(b instanceof B){

System.out.println("true 2");

}

else{

System.out.println("false 2");

}

a=new B();

if(a instanceof A){

System.out.println("true 3");

}

else{

System.out.println("false 3");

}

if(a instanceof B){

System.out.println("true 4");

}

else{

System.out.println("false 4");

}

b=new B();

if(b instanceof A){

System.out.println("true 5");

}

else{

System.out.println("false 5");

}

if(b instanceof B){

System.out.println("true 6");

}

else{

System.out.println("false 6");

}

}

}

输出结果是：

false 1

false 2

true 3

true 4

true 5

true 6

http://blog.csdn.net/j2eejia/article/details/1733871