c++ - 输出省略 "January"

Question

好的，这个程序的唯一问题是在最后我试图确定哪些月份的降雨总量最低或最高。除非“Jan”(一月)是最高的或最低的，否则我的输出都很好。然后将留空。所有其他变体都很好用。知道为什么会这样吗？我的数组的索引是否在某处？在此先感谢您的任何建议。

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

int main()
{
    //declare and initialize variable and arrays
    string year[] = {"Jan", "Feb", "Mar", "April", "May", "June",
            "July", "August", "Sept", "Oct", "Nov", "Dec"}; 

    const int totalMonths = 12;

    double month[totalMonths]; 

    double average; 
    double total = 0;

    cout << "This program will calculate the total annual rainfall,\n";
    cout << "calculate the monthly average rainfall, and display\n";
    cout << "which month had the lowest amount of rainfall and which\n";
    cout << "month had the highest amount of rainfall. Please enter the\n";
    cout << "rainfall data in inches." << endl;
    cout << "----------------------------------------------------------" << endl;

    // prompt user for input, keep a total sum of data entered
    for(int i = 0; i < 12; i++)
    {
        cout << "Enter total rainfall for " << year[i] << endl;
        cin >> month[i];
        total += month[i];
    while(month[i] < 0)
    {
        cout << "Rainfall cannot be negative!\n";
        cout << "Please re-enter positive numbers" << endl;
        cin >> month[i];
    }       

    }

    //average the total rainfall
    average = total / totalMonths;

    cout << setprecision(1) << fixed;
    cout << "Total Annual rainfall is: " << total << endl;
    cout << "The average rainfall per month is: " << average << endl;

    //determine which month had the lowest and highest amount of rainfall
    double highest = 0;
    string highMonth;
    highest = month[0];
    for(int count = 0; count < totalMonths; count++)
    {
        if(month[count] > highest)
        {
            highest = month[count];
            highMonth = year[count];

        }

    }

    double lowest = 0;
    string lowMonth;
    lowest = month[0];
    for(int count = 0; count < totalMonths; count++)
    {
        if(month[count] < lowest)
        {
            lowest = month[count];
            lowMonth = year[count];
        }
    }

    cout << "The month with the highest rainfall is: " << highMonth << endl;
    cout << "The month with the lowest rainfall is: " << lowMonth << endl;  

return 0;
}

输出示例:

This program will calculate the total annual rainfall,
calculate the monthly average rainfall, and display
which month had the lowest amount of rainfall and which
month had the highest amount of rainfall. Please enter the
rainfall data in inches.
----------------------------------------------------------
Enter total rainfall for Jan
1
Enter total rainfall for Feb
2
Enter total rainfall for Mar
3
Enter total rainfall for April
4
Enter total rainfall for May
5
Enter total rainfall for June
6
Enter total rainfall for July
7
Enter total rainfall for August
89
Enter total rainfall for Sept
12
Enter total rainfall for Oct
13
Enter total rainfall for Nov
14
Enter total rainfall for Dec
15
Total Annual rainfall is: 171.0
The average rainfall per month is: 14.2
The month with the highest rainfall is: August
The month with the lowest rainfall is: <-------- //BLANK!

Answer 1

我在这个程序中发现了两个问题:

1. 您来这里的原因 -- 您不允许第一个月匹配:

   double highest = 0;
   string highMonth;
   highest = month[0];
   for(int count = 0; count < totalMonths; count++)
   {
       if(month[count] > highest)
       {
           highest = month[count];
           highMonth = year[count];
       }
   }
   

   在这种情况下，month[count] > highest 测试永远不会对 1 月为真。修改测试:

       if(month[count] >= highest)
   

   这允许第一个月匹配。记住这一点，你可能会再次犯这个错误——我知道我犯过。 (另一种情况的修复方法类似。)

2. 您还没有遇到的另一个问题，但我相信您的教授会注意到:您没有正确处理负数:

   for (int i = 0; i < 12; i++)
   {
       cout << "Enter total rainfall for " << year[i] << endl;
       cin >> month[i];
       total += month[i];
       while (month[i] < 0)
       {
           cout << "Rainfall cannot be negative!\n";
           cout << "Please re-enter positive numbers" << endl;
           cin >> month[i];
       }
   }
   

   如果用户输入负数会怎样？ total += month[i] 行将仍然影响总数(因此影响平均值)，即使您的输出声称不允许负数。这可能很难在简单的手动测试中发现，除非您也手动计算正确 数字。 (提示:当您可以根据手算结果检查输入时，这几乎总是值得的。)