使用函数时从整数转换为字符串

Posted 2023-02-22

【中文标题】使用函数时从整数转换为字符串

【英文标题】：Convert to string from integer while using functions

【发布时间】：2018-04-23 07:32:43

【问题描述】：

感谢大家对我之前帖子的帮助！从函数中提取信息时，我仍然无法从整数转换为字符串。我正在尝试将月份的实际名称显示到输出中，而不是与其关联的数字。我不确定如何成功转换为字符串。它在下面使用数字，但我无法让它在屏幕上显示字符串。

例如，我需要有以下句子：“1 月 月份的最大降雨量为 12 英寸”

edit：总而言之，我无法让函数带入字符串，而不是整数值。我的代码顶部声明的函数是我的教授让我们使用的，所以我不能对它们的声明方式做任何不同的事情。

// Declare const variables
const int TOTALMONTHS = 12;

// Declare array for months and rainfall
string months[] =  "January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December" ;
double rainFall[TOTALMONTHS];

// Declare functions
double getLowest(double[], int, int&);
double getHighest(double[], int, int&);

int main()

    int subscript;
    for (int months = 0; months < TOTALMONTHS; months++)
    
         // Get this month's rainfall.
         cout << "Enter the rainfall (in inches) for ";
         cout << monthNames[months] << ": ";
         cin >> rainFall[months];
    

    // Display the largest amount of rainfall.
    cout << "The largest amount of rainfall was ";
    cout << getHighest(rainFall, TOTALMONTHS, subscript)
        << " inches in month ";
    cout << (subscript + 1) << "." << endl;

    // Display the smallest amount of rainfall.
    cout << "The smallest amount of rainfall was ";
    cout << getLowest(rainFall, TOTALMONTHS, subscript)
        << " inches in month ";
    cout << (subscript + 1) << "." << endl << endl;

    // End of program
    system("pause");
    return 0;


double getLowest(double rainFall[], int TOTALMONTHS, int &subscript)

    double smallest;
    smallest = rainFall[0];

    for (int months = 0; months < TOTALMONTHS; months++)
    
        if (rainFall[months] < smallest)
        
            smallest = rainFall[months];
            subscript = months; 
        
    
    return smallest;


double getHighest(double rainFall[], int TOTALMONTHS, int &subscript)

    double largest;
    largest = rainFall[0];

    for (int months = 0; months < TOTALMONTHS; months++)
    
        if (rainFall[months] > largest) 
        
            largest = rainFall[months];
            subscript = months; 
        
    

    return largest;

【问题讨论】：

Alternative to itoa() for converting integer to string C++?的可能重复

你已经在第一个循环中成功地做到了。再做同样的事情。

【参考方案1】：

请注意，我还在函数中添加了下标 = 0； 就这么简单：

#include <string>
#include <iostream>
#include <limits>

using namespace std;

// Declare const variables
const int TOTALMONTHS = 12;

// Declare array for months and rainfall
string monthNames[] =  "January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December" ;
double rainFall[TOTALMONTHS];

// Declare functions
double getLowest(double[], int, int&);
double getHighest(double[], int, int&);

int main()

    int subscript;
    for (int months = 0; months < TOTALMONTHS; months++)
    
        // Get this month's rainfall.
        cout << "Enter the rainfall (in inches) for ";
        cout << monthNames[months] << ": ";
        cin >> rainFall[months];
    

    // Display the largest amount of rainfall.
    cout << "The largest amount of rainfall was ";
    cout << getHighest(rainFall, TOTALMONTHS, subscript)
        << " inches in month ";
    cout << monthNames[subscript] << "." << endl;

    // Display the smallest amount of rainfall.
    cout << "The smallest amount of rainfall was ";
    cout << getLowest(rainFall, TOTALMONTHS, subscript)
        << " inches in month ";
    cout << monthNames[subscript] << "." << endl << endl;

    // End of program
    //system("pause");
    return 0;


double getLowest(double rainFall[], int TOTALMONTHS, int &subscript)

    double smallest;
    smallest = rainFall[0];
    subscript = 0;

    for (int months = 0; months < TOTALMONTHS; months++)
    
        if (rainFall[months] < smallest)
        
            smallest = rainFall[months];
            subscript = months; 
        
    
    return smallest;


double getHighest(double rainFall[], int TOTALMONTHS, int &subscript)

    double largest;
    largest = rainFall[0];
    subscript = 0;

    for (int months = 0; months < TOTALMONTHS; months++)
    
        if (rainFall[months] > largest) 
        
            largest = rainFall[months];
            subscript = months; 
        
    

    return largest;

【参考方案2】：

使用简单的索引

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

std::string IntToString(int id)

    if ( id < 1 || id > 12 )
    
        return "BadMonth";
    
    return months[id-1];


int main()

    std::cout << IntToString(1) << std::endl;
    std::cout << IntToString(2) << std::endl;
    std::cout << IntToString(3) << std::endl;
    std::cout << IntToString(0) << std::endl;

输出是：

January
February
March
BadMonth

在您的上下文中，我认为您应该替换

cout << (subscript + 1) << "." << endl << endl;

与

cout << IntToString(subscript + 1) << "." << endl << endl;

添加我的方法后。 或者干脆

cout << months[subscript] << "." << endl << endl;

无需添加任何新代码。

【讨论】：

在这个作业中，我必须使用我的代码中包含的函数。

@Denise ，将函数 IntToString(int id) 添加到您的代码中并使用它。或者只使用索引months[id-1] 如果您想从 1 开始月份，则只有 id 必须是 -1。或者我​​没有在评论中得到问题？

哦，抱歉。我想我误解了你的回答。我会按照你的建议工作。谢谢！

@Denise ，请在帖子末尾查看我的编辑更新。我写了解释