虚函数调用示例程序

#include <stdio.h>
class base {
public:
	base() {
		f();
		printf("base\n");
	}
	virtual void f() {
		printf("base::f()\n");
	}
	virtual void t() {
		printf("base::t()\n");
		f();
	}
};
class subtype:public base {
public:
	subtype() {
		f();
		printf("subtype\n");
	}
	//重载父类的虚函数
	virtual void f() {
		printf("subtype::f()\n");
	}
};
int main() {
	subtype t;
	t.f(); //sub::f
	printf("----\n");

	base b;
	b.f(); //base::f
	printf("----\n");

	base *p_sub = new subtype();
	p_sub->t();
	p_sub->f(); //sub::f
	printf("----\n");

	base *p_base = new base();
	p_base->f(); //base::f
}