平均函数找不到正确的平均C++

Question

float findGradeAvg(GradeType array, int numOfGrades)

{
    float sum = 0; 

    for (int i = 0; i < numOfGrades; i++)

       sum = sum + array[i];

    return (sum / numOfGrades); 
}

以上是我找到输入成绩平均值的代码.功能骨架不能改变,所以我坚持使用浮动和两个输入.

这是我的主要内容:

int main()

{
    StringType30 firstname, lastname;  // two arrays of characters defined
    int numOfGrades;                   // holds the number of grades
    GradeType  grades;                 // grades is defined as a one dimensional array 
    float average;                     // holds the average of a student's grade
    char moreinput;                    // determines if there is more input

    // Input the number of grades for each student

    cout << "Please input the number of grades each student will receive." << endl
         << "This number must be a number between 1 and " << MAXGRADE << " inclusive" << endl;

    cin >> numOfGrades;

    while (numOfGrades > MAXGRADE || numOfGrades < 1)
    {
        cout << "Please input the number of grades for each student." << endl
             << "This number must be a number between 1 and " << MAXGRADE << " inclusive" << endl;

        cin >> numOfGrades;

    }

    // Input names and grades for each student
    cout << "Please input a y if you want to input more students"
         << " any other character will stop the input" << endl;
    cin >> moreinput;

    while ( moreinput == 'y' || moreinput == 'Y')

    {
        cout << "Please input the first name of the student" << endl;
        cin >> firstname;
        cout << endl << "Please input the last name of the student" << endl;
        cin >> lastname;

        for (int count = 0; count < numOfGrades; count++)

        {

            cout << endl << "Please input a grade" << endl;
            int i = 0;
            cin >> grades[i];
            i++;

        }

        cout << firstname << ' ' << lastname << " has an average of "; 
        float average = findGradeAvg(grades, numOfGrades);
        cout << average;
        cout << "which gives the letter grade of " << findLetterGrade(average);

        cout << endl << endl << endl;
        cout << "Please input a y if you want to input more students"
             << " any other character will stop the input" << endl;
        cin >> moreinput;

    }
    system("pause");
    return 0;
}

我不知道为什么它给出了不正确的平均值,因为我在一个具有正确结果的不同程序中使用了这个函数.现在我输入100,90和90,并收到以下作为输出.

-7.15828e + 007

Answer 1

这是一个问题

for (int count = 0; count < numOfGrades; count++)
{
    cout << endl << "Please input a grade" << endl;
    int i = 0;
    cin >> grades[i];
    i++;
}

在这里你定义(并重复定义)循环i 内的变量!这意味着i永远是零.你可能想要,例如

cin >> grades[count];