java 继承 instanceof 问题

[lvjun106]

class Inter{
int a=10;
}
public class Test extends Inter{
int c=8;
public int getC(){
return c;
}
public static void main(String args[]){
Inter b=new Inter();
b=new Test();
if(b instanceof Test){
System.out.print("ok!");
//System.out.print(c.getC());为什么这句不能实现？
}
if(b instanceof Inter){
System.out.print("super is also ok!");
}
}
}

[z_lping]

This is nothing to do with "instanceof" operator.

Reference Variable "b" is of type "Inter". b.getC() fails because there is no method called "getC()" defined in class Inter. To make it work, you have to cast b to type "Test".

if (b instanceof Test) {
    System.out.println("OK!");
    System.out.println(((Test)b).getC());
}

[lvjun106]

THANK YOU!
I mistake the "b=new Test()";