第五周 阅读程序 4 const 的用法

#include <iostream>#include <string>using namespace std;class Student{public:    Student() {}    Student( const string& nm, int sc = 0 ): name(nm), score(sc){}    //（1）下面的const干神马？_______保护数据不被修改______    void set_student( const string& nm, int sc = 0 )     {        name = nm;        score = sc;}     //（2）下面的const分别干神马？___定义为常函数_______    const string& get_name() const    {        return name;   }     int get_score() const    {        return score;    }private:    string name;    int score;}; //（3）下面的const干神马？_______引用数据，防止数据被修改，起到保护数据的功能______void output_student(const Student& student ) {    cout << student.get_name() << "\t";    cout << student.get_score() << endl;} int main(){    Student stu( "Wang", 85 );    output_student( stu );    return 0;}