C++作业（第七章）7-11

题目：7-11 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。

 

#include <iostream>
using namespace std;
class BaseClass
{
public:
    void fn1();
    void fn2();

};
void BaseClass::fn1()
{
    cout << "调用基类的函数fn1()" << endl;
}
void BaseClass::fn2()
{
    cout << "调用基类的函数fn2()" << endl;
}

class DerivedClass : public BaseClass
{
public:
    void fn1();
    void fn2();
};
void DerivedClass::fn1()
{
    cout << "调用派生类的函数fn1()" << endl;
}
void DerivedClass::fn2()
{
    cout << "调用派生类的函数fn2()" << endl;
}
int main()
{
    DerivedClass aDerivedClass;
    DerivedClass *pDerivedClass = &aDerivedClass;
    BaseClass *pBaseClass = &aDerivedClass;
    
    aDerivedClass.fn1();
    aDerivedClass.fn2();
    pBaseClass->fn1();
    pBaseClass->fn2();
    pDerivedClass->fn1();
    pDerivedClass->fn2();
    
    return 0;

}