class instanceofDemo {	public static void main(String[] args) 	{		CFather c1 = new CChild1();//父类对象引用指向子类对象				test(c1);		CFather c2 = new CChild2();		test(c2);	}	public static void test(CFather c){		c.print();                //使用instanceof判断c是否是CChild2的一个实例		if (c instanceof CChild2){			CChild2 c2 = (CChild2)c;			c2.print1();		}	}}abstract class CFather{	abstract public void print();//抽象方法}class CChild1 extends CFather{		//	public void print(){		System.out.println("this is Child1");	}}class CChild2 extends CFather{	public void print(){		System.out.println("this is Child2");	}	//本类的其他方法	public void print1(){		System.out.println("hello java");	}}