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c++ - 使用 switch 将整数更改为字符串

问题描述

我需要将整数转换为字符串。该整数是 most_occurred_number ，我无法确定将哪个整数插入代码。我已将 most_occurred_number 作为整数，但 cout 中没有任何变化。我尝试放置month1 [i]，但即使它在代码中，它也会出现未声明标识符的错误。

#include <string>
#include <algorithm>
#include <map>
#include <array>
#include <iomanip>

using namespace std;

int dayofweek(int d, int m, int y)
{
    static int t[] = { 0, 3, 2, 5, 0, 3,
                       5, 1, 4, 6, 2, 4 };
    y -= m < 3;
    return ( y + y / 4 - y / 100 +
             y / 400 + t[m - 1] + d) % 7;
}

std::string to_date_string1(int most_occurred_number1)
{
    switch(most_occurred_number1)
    {
    case 1:
        return "Monday";
    case 2:
        return "Tuesday";
    case 3:
        return "Wednesday";
    case 4:
        return "Thursday";
    case 5:
        return "Friday";
    case 6:
        return "Saturday";
    case 7:
        return "Sunday";
    }
}

std::string to_date_string2(int most_occurred_number2)
{
    switch(most_occurred_number2)
    {
    case 1:
        return "Monday";
    case 2:
        return "Tuesday";
    case 3:
        return "Wednesday";
    case 4:
        return "Thursday";
    case 5:
        return "Friday";
    case 6:
        return "Saturday";
    case 7:
        return "Sunday";
    }
}

void most_occurred_number1(int month1[], int size1)
{
  int max_count1 = 0;
  cout << "\nMost occurred number: ";
  for (int i=0; i<size1; i++)
  {
   int count1=1;
   for (int j=i+1;j<size1;j++)
       if (month1[i]==month1[j])
           count1++;
   if (count1>max_count1)
      max_count1 = count1;
  }

  for (int i=0;i<size1;i++)
  {
   int count1=1;
   for (int j=i+1;j<size1;j++)
       if (month1[i]==month1[j])
           count1++;
   if (count1==max_count1)
       cout << month1[i] << endl;
  }
 }

void most_occurred_number2(int month2[], int size2)
{
  int max_count2 = 0;
  cout << "\nMost occurred number: ";
  for (int i=0; i<size2; i++)
  {
   int count2=1;
   for (int j=i+1;j<size2;j++)
       if (month2[i]==month2[j])
           count2++;
   if (count2>max_count2)
      max_count2 = count2;
  }

  for (int i=0;i<size2;i++)
  {
   int count2=1;
   for (int j=i+1;j<size2;j++)
       if (month2[i]==month2[j])
           count2++;
   if (count2==max_count2)
       cout << month2[i] << endl;
  }
 }

int main()
{
    int day1 = dayofweek(03, 02, 2020); //month 1 days
    int day2 = dayofweek(04, 02, 2020);
    int day3 = dayofweek(04, 02, 2020);
    int day4 = dayofweek(05, 02, 2020);
    int day5 = dayofweek(11, 02, 2020);
    int day6 = dayofweek(12, 02, 2020);
    int day7 = dayofweek(13, 02, 2020);
    int day8 = dayofweek(20, 02, 2020);
    int day9 = dayofweek(21, 02, 2020);
    int day10 = dayofweek(27, 02, 2020);

    int day11 = dayofweek(02, 03, 2020); //month 2 days
    int day12 = dayofweek(02, 03, 2020);
    int day13 = dayofweek(05, 03, 2020);
    int day14 = dayofweek(10, 03, 2020);
    int day15 = dayofweek(11, 03, 2020);
    int day16 = dayofweek(11, 03, 2020);
    int day17 = dayofweek(17, 03, 2020);
    int day18 = dayofweek(19, 03, 2020);
    int day19 = dayofweek(24, 03, 2020);
    int day20 = dayofweek(25, 03, 2020);

    int month1 [] = {day1, day2, day3, day4, day5, day6, day7, day8, day9, day10};
    int n1 = sizeof(month1)/sizeof(month1[0]);
    cout << "Original array: ";
    for (int i=0; i < n1; i++)
    cout << month1[i] <<" ";
    most_occurred_number1(month1, n1);

    int month2 [] = {day11, day12, day13, day14, day15, day16, day17, day18, day19, day20};
    int n2 = sizeof(month2)/sizeof(month2[0]);
    cout << "Original array: ";
    for (int i=0; i < n2; i++)
    cout << month2[i] <<" ";
    most_occurred_number2(month2, n2);

}```

标签： c++switch-statementdayofweek

解决方案

我需要将整数转换为字符串。

然后使用std::to_string https://en.cppreference.com/w/cpp/string/basic_string/to_string

整数是 most_occurred_number

int这段代码中没有这种类型的变量。我可以看到most_occurred_number1和most_occurred_number2，它们是函数参数——它们似乎（几乎）在switch语句中得到了正确处理。几乎 - 因为你to_date_string1并不to_date_string2总是返回一个值 - 这是 c++ 中的未定义行为 - 你可以添加return "?"或抛出异常，以防函数没有在适当范围内调用值。

我已将 most_occurred_number 作为整数，但 cout 中没有任何变化

您应该在代码中显示您尝试放置的位置most_occurred_number

我尝试放置month1 [i]，但即使它在代码中，它也会出现未声明标识符的错误。

Arraymonth1是 的一个参数，most_occurred_number1也是 的一个变量main，这些是它唯一可见的地方。

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