Question

我正在编写一个程序，将短日期（mm / dd / yyyy）转换为长日期（2014年3月12日）并打印出日期。

在给定以下用户输入的情况下，程序必须工作： 2014年10月23日 2014年9月25日 2015年12月8日 2016年1月1日

我让程序使用第一个用户输入，但我不知道如何处理没有＆＃34; 0＆＃34;的用户输入。在字符串的第一个位置。

#include <iostream>
#include <string>

using namespace std;

int main() 
{
    string date; 
    cout << "Enter a date (mm/dd/yyyy): " << endl;
    getline(cin, date);

    string month, day, year;

    // Extract month, day, and year from date
    month = date.substr(0, 2);
    day = date.substr(3, 2);
    year = date.substr(6, 4);

    // Check what month it is 
    if (month == "01") {
        month = "January";
    }
    else if (month == "02") {
        month = "February";
    } 
    else if (month == "03") {
        month = "March";
    } 
    else if (month == "04") {
        month = "April";
    } 
    else if (month == "05") {
        month = "May";
    } 
    else if (month == "06") {
        month = "June";
    } 
    else if (month == "07") {
        month = "July";
    } 
    else if (month == "08") {
        month = "August";
    } 
    else if (month == "09") {
        month = "September";
    } 
    else if (month == "10") {
        month = "October";
    } 
    else if (month == "11") {
        month = "November";
    } 
    else {
        month = "December";
    }

    // Print the date
    cout << month << " " << day << "," << year << endl;
    return 0;
}

我非常感谢任何帮助。

Answer 1

正如Red Serpent在评论中写道：使用std::string::find搜索/，例如

#include <iostream>

int main()
{
    std::string date = "09/28/1983";

    int startIndex = 0;
    int endIndex = date.find('/');
    std::string month = date.substr(startIndex, endIndex);

    startIndex = endIndex + 1;
    endIndex = date.find('/', endIndex + 1);
    std::string day = date.substr(startIndex, endIndex - startIndex);

    std::string year = date.substr(endIndex + 1, 4);

    std::cout << month.c_str() << " " << day.c_str() << "," << year.c_str() << std::endl;

    return 0;
}

Answer 2

您还可以利用流转换，以获得效率更低但更简单的解决方案：

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

int main() {

    string months[] = {"", "January", "February", "Mars", "April", "May", "June", "Jully", "August", "September", "October", "December"};

    cout << "Enter a date (mm/dd/yyyy): " << endl;
    char c;
    int day, month, year;
    cin >> day >> c >> month >> c >> year;
    // error handling is left as an exercice to the reader.
    cout << months[month] << " " << day << ", " << year << endl;
    return 0;
}

如何在字符串中搜索字符？

2 个答案: