Java之"instanceof"和"isInstance"代码举例
源码：
1 /** 2 * @Date:2018-04-20 3 * @Description:判断Instance 4 * - instanceof方法返回一个boolean类型的值，意在告诉我们对象是不是某个特定的类型实例。 5 * - isInstance方法则是Class类中的一个Native方法，也是用于判断对象类型的。 6 **/ 7 public class InstanceDemo { 8 9 static void test(Object x) { 10 System.out.println("Testing x of type " + x.getClass()); 11 System.out.println("x instanceof A " + (x instanceof A)); 12 System.out.println("x instanceof B " + (x instanceof B)); 13 System.out.println("A.isInstance(x) " + A.class.isInstance(x)); 14 System.out.println("B.isInstance(x) " + 15 B.class.isInstance(x)); 16 System.out.println("x.getClass() == A.class " + 17 (x.getClass() == A.class)); 18 System.out.println("x.getClass() == B.class " + 19 (x.getClass() == B.class)); 20 System.out.println("x.getClass().equals(A.class)) " + 21 (x.getClass().equals(A.class))); 22 System.out.println("x.getClass().equals(B.class)) " + 23 (x.getClass().equals(B.class))); 24 } 25 26 public static void main(String[] args) { 27 test(new A()); 28 System.out.println("-------------------------"); 29 test(new B()); 30 } 31 32 } 33 34 class A { 35 } 36 37 class B extends A { 38 }
运行结果：
1 Testing x of type class org.study2.reflection.A 2 x instanceof A true 3 x instanceof B false 4 A.isInstance(x) true 5 B.isInstance(x) false 6 x.getClass() == A.class true 7 x.getClass() == B.class false 8 x.getClass().equals(A.class)) true 9 x.getClass().equals(B.class)) false 10 ------------------------- 11 Testing x of type class org.study2.reflection.B 12 x instanceof A true 13 x instanceof B true 14 A.isInstance(x) true 15 B.isInstance(x) true 16 x.getClass() == A.class false 17 x.getClass() == B.class true 18 x.getClass().equals(A.class)) false 19 x.getClass().equals(B.class)) true
