我不知道如何使我的程序使用局部變量而不是全局變量

Question

我的程序需要使用局部變量而不是全局變量。 但是，當我嘗試執行此操作時，似乎找不到正確的參數來從main和function來回傳遞數據。 我不斷收到錯誤消息，說“ int的參數類型與float類型的參數不兼容”。 請幫助我了解在這里做什么。 感謝您的寶貴時間，我非常感謝。

我試過搜索錯誤代碼，但只找到關於指針問題的答案/問題，而我還沒有學過。 我已經工作了幾個小時，只是為了使變量在“ int main”中工作，但無濟於事。

//This program asks user how many grades there are, 
//inputs grades, and displays median of said grades.

//"int main" is at the bottom of the program, preceded by
//variables, function headers, and a single array.
#include <iostream>
using namespace std;

void grdTaker(float [], int);
void sortArray(float[], int);
void median(float[], int);

//Main
int main()
{
    //Variables
//int grdsCounted; //Number of grades from user.
    const int arraySize = 20;
    int grdsCounted; //Number of grades from user.
    float grades[arraySize]; //Max grades that can be entered.

    grdTaker(grdsCounted, grades[]);
    sortArray(grades, grdsCounted);
    median(grades, grdsCounted);

    system("pause");
}

void grdTaker(float array[], int size) //Function gathers grades.
{
    //const int arraySize = 20;
    //int grdsCounted; //Number of grades from user.
    //float grades[arraySize]; //Max grades that can be entered.

    cout << "You may input up to 20 grades. \n";
    cout << "First enter the number of grades you have: ";
    cin >> grdsCounted;

    while (grdsCounted > arraySize)
    {
        cout << "That is more than 20 grades, try again: \n";
        cin >> grdsCounted;
    }

    cout << "Enter each grade: \n";

    //requests how many grades there are and stores them in array
    for (int grdCount = 0; grdCount < grdsCounted; grdCount++)
    {
        cin >> grades[grdCount];
    }
};

void sortArray(float array[], int size) //Function sorts array values.
{
    bool swap;
    float temp;

    do
    {
        swap = false;
        for (int count = 0; count < (size - 1); count++)
        {
            if (array[count] > array[count + 1])
            {
                temp = array[count];
                array[count] = array[count + 1];
                array[count + 1] = temp;
                swap = true;
            }
        }
    } while (swap);
}

void median(float array[], int size) //Outputs the median of entered grades.
{
    int med = size / 2;
    int odd = med - 1;

    cout << "The median grade is: ";

    if (size % 2 == 1)
    {
        cout << array[med] << endl;
    }
    else
    {
        cout << (array[med] + array[odd]) / 2 << endl;
    }

}

Answer 1

您分配給浮點數的問題可能是由於在C ++中以這種方式創建了數組。 嘗試使用new de c ++方式聲明數組。

您是否想過返回值！ 看看這個！ 例如，將第一個功能划分為2！ 編程始終是將問題分解為小問題。

int numberGradesFromUser() {

    int grdsCounted;
    int arraySize = 20;

    cout << "You may input up to 20 grades. \n";
    cout << "First enter the number of grades you have: ";
    cin >> grdsCounted;

    while (grdsCounted > arraySize)
    {
        cout << "That is more than 20 grades, try again: \n";
        cin >> grdsCounted;
    }
    return grdsCounted;
}

float* grdTaker(int grdsCounted) //Function gathers grades.
{

    float * grades = new float[grdsCounted];

    cout << "Enter each grade: \n";

    //requests how many grades there are and stores them in array
    for (int grdCount = 0; grdCount < grdsCounted; grdCount++)
    {
        cin >> grades[grdCount];
    }
    return grades;

};

int main()
{
    //Variables

    int grdsCounted; //Number of grades from user.      

    grdsCounted = numberGradesFromUser();
    float *gradess = new float[grdsCounted];

    sortArray(gradess, grdsCounted);
    median(gradess, grdsCounted);

    system("pause");
}

有了這個，我想其余的功能應該可以工作。 以您的方式調整它們！

同樣，優良作法是在標頭中聲明函數，或者至少在main之上聲明函數，而不是在下面聲明！

Answer 2

試試看：

//This program asks user how many grades there are, 
//inputs grades, and displays median of said grades.

//"int main" is at the bottom of the program, preceded by
//variables, function headers, and a single array.
#include <iostream>
using namespace std;

void grdTaker(float [], int, const int);
void sortArray(float[], int);
void median(float[], int);

//Main
int main()
{
    //Variables
//int grdsCounted; //Number of grades from user.
    const int arraySize = 20;
    int grdsCounted; //Number of grades from user.
    float grades[arraySize]; //Max grades that can be entered.

    grdTaker(grades,arraySize);
    sortArray(grades, grdsCounted);
    median(grades, grdsCounted);

    system("pause");
}

void grdTaker(float array[], const int arraySize) //Function gathers grades.
{
    //const int arraySize = 20;
    //int grdsCounted; //Number of grades from user.
    //float grades[arraySize]; //Max grades that can be entered.
    int grdsCounted;
    cout << "You may input up to 20 grades. \n";
    cout << "First enter the number of grades you have: ";
    cin >> grdsCounted;

    while (grdsCounted > arraySize)
    {
        cout << "That is more than 20 grades, try again: \n";
        cin >> grdsCounted;
    }

    cout << "Enter each grade: \n";

    //requests how many grades there are and stores them in array
    for (int grdCount = 0; grdCount < grdsCounted; grdCount++)
    {
        cin >> array[grdCount];
    }
};

void sortArray(float array[], int size) //Function sorts array values.
{
    bool swap;
    float temp;

    do
    {
        swap = false;
        for (int count = 0; count < (size - 1); count++)
        {
            if (array[count] > array[count + 1])
            {
                temp = array[count];
                array[count] = array[count + 1];
                array[count + 1] = temp;
                swap = true;
            }
        }
    } while (swap);
}

void median(float array[], int size) //Outputs the median of entered grades.
{
    int med = size / 2;
    int odd = med - 1;

    cout << "The median grade is: ";

    if (size % 2 == 1)
    {
        cout << array[med] << endl;
    }
    else
    {
        cout << (array[med] + array[odd]) / 2 << endl;
    }

}

說明： 我添加了ARRAYSIZE到grdTaker功能，並在那里宣布grdsCounted。