写的一个C++简单类

#include <iostream>
using std::cout;
using std::cin;
using std::endl;

#include <string>
using std::string;
using std::getline;


class GradeBook
{
private:
        string courseName;
public:
        GradeBook():courseName(""){};
        GradeBook(string s):courseName(s){};
        void setName(string newName)
        {
       courseName = newName;
        }
        void displayMessage()//形参
        {
                cout << "Welcome to the grade book for " << courseName << "!" 
                        <<endl;
        }
};


int main()
{
        string nameOfCourse;//创建string类型变量，用语存储输入课程名称
    
        cout << "Please enter the course name:" << endl;//提示输入课程名称
        getline(cin,nameOfCourse);//通过getline库函数执行输入，从用户那里读取名称赋值给nameOfCourse
        cout << endl;
        GradeBook myGradeBook1(nameOfCourse);
        myGradeBook1.displayMessage();

        GradeBook myGradeBook2();
        myGradeBook2.setName(nameOfCourse);
        myGradeBook2.displayMessage();
        return 0;

}