【问题描述】
定义一个基类BaseClass,从它派生出类DerivedClass,BaseClass有成员函数fn1()、fn2(),DerivedClass也有成员函数fn1()、fn2(),在主程序中定义一个DerivedClass的对象,分别用DerivedClass的对象以及BaseClass和DerivedClass的指针来调用fn1()、fn2(),观察运行结果。
主函数如下,请勿修改:
int main(){
DerivedClass D;
DerivedClass *pD=&D;
BaseClass *pB=&D;
D.fn1();
D.fn2();
pD->fn1();
pD->fn2();
pB->fn1();
pB->fn2();
return 0;
}
完成此题是如此的简单,几行代码就可搞定,但是对主函数的输出,需要你仔细的分析并掌握哦!如果反过来,给你代码,请分析并写出程序运行结果,是否ok?
【样例输出】
Call Derive fn1()
Call Derive fn2()
Call Derive fn1()
Call Derive fn2()
Call Base fn1()
Call Base fn2()
代码如下
#include<iostream>
using namespace std;
class BaseClass
{
public:
void fn1() {
cout<<"Call Base fn1()"<<endl;}
void fn2() {
cout<<"Call Base fn2()"<<endl;}
};
class DeriverdClass : public BaseClass
{
public:
void fn1() {
cout<<"Call Derive fn1()"<<endl;}
void fn2() {
cout<<"Call Derive fn2()"<<endl;}
};
int main()
{
DeriverdClass D;
DeriverdClass *pD = &D;
BaseClass *pB = &D;
D.fn1();
D.fn2();
pD->fn1();
pD->fn2();
pB->fn1();
pB->fn2();
return 0;
}