使用数组C ++编写的流文本编写问题

时间:2013-12-19 04:58:11

标签: c++ visual-c++ visual-studio-2012

好吧,所以我臭名昭着的代码项目我已经有两次问题已经在很大程度上重新格式化了。现在,它看起来像这样:

#include <iostream>
#include <string>
#include <fstream>

using namespace std;


struct Course
{
    string name;
    double grade;
    int block;
};

Course enter_course()
{
    Course foo;

    cout << "What is the name of the course you wish to enter?\n";
    cin >> foo.name;
    cout << "What block is " << foo.name << " ?\n";
    cin >> foo.block;
    cout << "What is your current grade as a percent?";
    cin >> foo.grade;

    return foo;
}

void display_courses(Course courseList[10], int courseCount)
{
    for (int i=0; i<courseCount; i++){
        cout << i+1 << "\t" << courseList[i].name 
            << "\t\tBlock: " << courseList[i].block
            << "\tGrade: " << courseList[i].grade << "%" << endl;
    }
}

double get_gpa(Course courseList[10], int courseCount)
{
    double gradePoints;
    double total = 0.0;
    for (int i=0; i<courseCount; i++){
        if (courseList[i].grade < 100){
            gradePoints = 4;
        } 
        if (courseList[i].grade < 90){
            gradePoints = 3;
        }
        if (courseList[i].grade < 80){
            gradePoints = 2;
        }
        if (courseList[i].grade < 70){
            gradePoints = 1;
        }
        if (courseList[i].grade < 90){
            gradePoints = 0;
        }
        total += gradePoints;
    }

    return total*1.0/courseCount;

}

void fileOutput()   
{   
    ofstream outputFile;
    outputFile.open("userGrades.txt");
    outputFile << myCourses[10] << endl;
    outputFile.close();
    cout << "Grades saved to file!" << endl;
}

void display_options()
{
    cout << "1. Exit\n";
    cout << "2. Enter a Course\n"; 
    cout << "3. Display Courses\n";
    cout << "4. Display GPA\n";
    cout << "5. Request a text file output\n";

    cout << "\n\n";
}

int main()
{
    bool exit=0;
    int option;
    int courseCount=0;
    Course myCourses[10]; //nobody should ever take more than 10 courses! 

    while (exit == 0)
    {
        cout << "GradeBook 2.0\n";
        display_options();
        cout << "Enter a command.\n";
        cin >> option;

        switch (option)
        {
            case 1: 
                exit = 1;
                break;
            case 2:
                myCourses[courseCount] = enter_course();
                courseCount++;
                break;
            case 3:
                display_courses(myCourses, courseCount);
                break;
            case 4:
                cout << get_gpa(myCourses, courseCount) << endl;
                break;
            case 5:
                fileOutput();
                break;
        }
    }

    return 0;
}

但是,在fileOutput()函数中,我遇到了同一行代码的这些错误:

错误C2065:'myCourses':未声明的标识符 IntelliSense:标识符“myCourses”未定义

我唯一能理解的是,我需要在别处宣布myCourses,但我不知道如何。

有人认为他们可以解决这个问题吗?如果是这样,编译代码并查看。此外,get_gpa函数似乎没有正常工作,如果您也可以查看它。

2 个答案:

答案 0 :(得分:1)

您的课程类没有ostream运算符,因此您无法在此行中调用该运算符:

   outputFile << myCourses[10] << endl;

您可以尝试删除该行并输入:

display_courses(myCourses,courseCount)

但遗憾的是打印到cout。因此,您确实需要重新编写display_courses以获取ostream&参数并输出到它,而不是cout

答案 1 :(得分:0)

fileOutput功能中执行以下操作:

for (int i = 0; i < courseCount; i++)
 {
     outputFile << myCourses[i].name << " " << myCourses[i].grade << " " << myCourses[i].block << endl;

 }

outputFile.close();

" "替换为您要用于分隔文件内容的任何内容。

或者,您可以调查运算符重载并查看重载ofstream运算符。