C++大学基礎教程_4_9タグ制御のサイクル

//GradeBook.h
#include<string>
using  std::string;

class GradeBook
{
public:
	GradeBook(string );//      
	void setCourseName(string );//      
	string getCourseName();//      
	void disPlayMessage();//    
	void determineClassAverage();//                   
private:
	string courseName;//course name for this GradeBook class
};

 
 

//GradeBook.cpp
#include<iomanip>
#include <iostream>
using namespace std;
#include "GradeBook.h"  //  include              ，   ！！！！！



GradeBook::GradeBook(string name)
{
	setCourseName(name);
}

//    ，    coursename    25，   25   
void GradeBook::setCourseName(string name)
{
	if(name.length()<=25)
		courseName = name;
	else 
	{
		courseName = name.substr(0,25);//select first 25 characters
		cout << "Name\"" << name << "\"exceeds maximum length(25).
"
			   << "limiting courseName to first 25characters.
" << endl;
	}
}

string  GradeBook::getCourseName()
{
	return courseName;
}

void GradeBook::disPlayMessage()
{
	cout << "welcome to the grade book for
" << getCourseName() << "!
"<< endl;
	
}

void GradeBook::determineClassAverage()
{
	int total = 0;//     
	int grade;//       
	int gradeCounter = 0 ;//         
	double average ;//       

	cout << "Enter the first grade or -1 to quit :" << endl;
	cin >> grade ;
	
	while(grade!=-1)
	{
		total = total +grade ;
		gradeCounter = gradeCounter +1 ;//     
		cout << "Enter the " << gradeCounter +1<< "th grade or -1 to quit :" << endl;
	    cin >> grade ;
	}
	if(gradeCounter != 0)
	{
		average = static_cast<double>(total)/gradeCounter ;
		cout << "
 Total of all " << gradeCounter << " grades entered is :" << total << endl;
		cout << "Class average is :" << setprecision(4) << fixed << average << endl;
	}
	else
		cout << "No grades were entered !" << endl;
	
}

 
 
 
 

// main.cpp
#include "GradeBook.h"

int main()
{
	GradeBook myGradeBook("C++      ");
	myGradeBook.disPlayMessage();
	myGradeBook.determineClassAverage();
	system("pause >>  cout ");
	return 0;
}