#include <iostream>
#include <string>
using namespace std;

class student
{
private:
    string name;
    int age;
public:
    student(){}
    student(string name,int age)
    {
        this->name = name;
        this->age = age;
    }

    string getName()
    {
        return this
 
->name;
    }

    int getAge()
    {
        return this->age;
    }

#if 1
    void showStudent()const //常函數,常函數重載
    {
//        this->name = "zhangsan";//error,常函數中不允許修改類的數據成員的值
        cout << "void showStudent()const" << endl;
        cout << this->name << " " << this
 
->age <<endl;
    }

#endif

#if 0
    void showStudent()  //一般函數
    {
        this->name = "zhangsan";    //一般函數中允許修改變量的值
        cout << "void showStudent()" <<endl;
        cout << this->name << " " << this->age <<endl;
    }
#endif
};

#if 0
int showint(int
 
 num1) const //error：常函數只能存在於類中
{
    cout << num1 << endl;
}
#endif

int main()
{
    student stu("zhangsan",22); //一般對象，可以調用非常函數，也可以調用常函數
    stu.showStudent();

    const student stu2("lisi",33);  //常對象,不能修改對象的值
    const int i = 10;
    stu2.showStudent();
}

常函數和常對象的應用