Question

我正在处理以下C ++作业问题：

＆＃34;编写一个程序，让用户将12个月中每个月的总降雨量输入一系列双打。该计划应计算并显示当年的总降雨量，月平均降雨量以及最高和最低量的月份。

输入验证：不接受月降雨量数字的负数。＆＃34;

我得到的错误是：

警告2警告C4244：＆＃39; =＆＃39; ：转换为＆＃39; double＆＃39;到＆＃39; int＆＃39;，可能丢失数据
警告4警告C4244：＆＃39; =＆＃39; ：转换为＆＃39; double＆＃39;到＆＃39; int＆＃39;，可能丢失数据
警告1警告C4244：＆＃39;初始化＆＃39; ：转换为＆＃39; double＆＃39;到＆＃39; int＆＃39;，可能的损失数据
警告3警告C4244：＆＃39;初始化＆＃39; ：转换自＆＃39;双＆＃39;到＆＃39; int＆＃39;，可能丢失数据

阅读这些内容，我想我可以安全地假设我的代码中有几个错误，即将双打整数转换成整数。我梳理了我的代码，寻找这些错误。我找到的那些int变量（根据Visual Studio 2012提供的行方向），我改为double;但它只会弄乱我的代码并产生更多错误。我甚至走出去，把每个int变量变成了一个双变量，只是被关于＆＃39;计数器的20多个错误所打扰。变量;错误说＆＃34;枚举类型。＆＃34;

非常感谢这里的任何帮助，这项任务将于本周四下午（10月9日）到期。

这个程序确实编译了，但它也给了我各种垃圾答案和多余的垃圾答案。

到目前为止，这是我的代码：

#include<iostream>
#include<string>
using namespace std;

//Function prototypes
void totalAndAverage(int, double []);
void getHighest(int, double [], string []);
void getLowest(int, double [], string []);


//Global integer
const int SIZE = 12;
int main()
{
    //Create arrays
    double rainfallAmount[SIZE];
    int index;
    string months[SIZE] = { "January", "February", "March",
                         "April", "May", "June", 
                         "July", "August", "September", 
                         "October", "November", "December" };

    //Get the amount of rain for each month
    for ( index = 0; index < SIZE; index++)
    {
        cout << "Please enter the amount of rain (in inches) for month " << (index + 1) << ": " << endl; //+1 to not skip an array element
        cin >> rainfallAmount[index];

            //input validation, do not accept negative numbers
            while (rainfallAmount[index] < 0)
            {
                cout << "You cannot have a negative amount of rainfall. Please enter the amount of rain." << endl;
                cin >> rainfallAmount[index];
            }

    }

    //Call function to find total and average
    totalAndAverage(index, rainfallAmount);

    //Call function to find highest
    getHighest(index, rainfallAmount, months);

    //Call function o find lowest
    getLowest(index, rainfallAmount, months);

system("pause");
return 0;

}



void totalAndAverage(int i, double rainData[])
{
    double total = 0, average;

    //Find the total and average
    for (i = 0; i < SIZE; i++)
    {
        total += rainData[i];
    }
    //Display total
    cout << "The total rainfall is: " << total << endl;

    //Find average and display
    average = total / SIZE;
    cout << "The average monthly rainfall is: " << average << endl;
}



void getHighest(int iCount, double rainData2[], string monthData[])
{
    string highestMonth;

    //Initialize highest
    int highestRain = rainData2[0];

    //Find the highest
    for (iCount = 0; iCount < SIZE; iCount++)
    {
        if (rainData2[iCount] > highestRain)
        {
            highestRain = rainData2[iCount];
            highestMonth = monthData[iCount];

            //Display highest
            cout << highestMonth << " had the most rainfall this year with " << highestRain << " inches." << endl;
        }

    }
}



void getLowest(int counter, double rainData3[], string monthDataCopy[])
{
    string lowestMonth;

    //Initialize highest
    int lowestRain = rainData3[0];

    //Find the highest
    for (counter = 0; counter < SIZE; counter++)
    {
        if (rainData3[counter] > lowestRain)
        {
            lowestRain = rainData3[counter];
            lowestMonth = monthDataCopy[counter];

            //Display highest
            cout << lowestMonth << " had the least rainfall this year with " << lowestRain << " inches." << endl;
        }

    }
}

Answer 1

您写道：

 int highestRain = rainData2[0];
 int lowestRain = rainData3[0];

由于您希望找到最高和最低值而不会舍入为整数，因此您的＆＃34;最好到目前为止＆＃34;变量需要加倍。您可以明确地声明它们：

 double highestRain = rainData2[0];
 double lowestRain = rainData3[0];

您还可以使用auto关键字。（参见docs for Visual Studio 2012。）这种风格的优点和缺点超出了这个答案的范围，但你可能应该注意语言特性。

 auto highestRain = rainData2[0];
 auto lowestRain = rainData3[0];

Answer 2

更改

int highestRain = rainData2[0];

要

double highestRain = rainData2[0];

同样的最低雨。

Answer 3

首先，当你这样做时：

string months[SIZE] = { "January", "February", "March",
                         "April", "May", "June",
                         "July", "August", "September", 
                         "October", "November", "December" };

您不需要“SIZE”，因此您可以将其更改为：

string months[] = { "January", "February", "March",
                    "April", "May", "June",
                    "July", "August", "September", 
                    "October", "November", "December" };

C ++可以计算数组中有多少元素。

而不是说：

cout << "Please enter the amount of rain (in inches) for month " << (index + 1) << ": " << endl;

将(index+1)替换为months[index]。谁想读“1”而不是“1月”？

除此之外，你没有任何错误！这些是警告，因此它们不会使您的程序停止工作。

要取消警告，请替换：

//Initialize highest
int highestRain = rainData2[0];

使用：

//Initialize highest
double highestRain = rainData2[0];

同样的事情：

//Initialize highest
int lowestRain = rainData3[0];

将其更改为double。这摆脱了警告但没有给你更多像你提到的错误。

警告：“从'double'转换为'int'，可能会丢失数据”

3 个答案: