146.正则表达式

#include <regex>
#include <iostream>
#include <cstdlib>
#include <locale>
using namespace std;

void main1()
{
    //精确匹配
    //regex reg("1234");
    //匹配四个数字
    //regex reg("\d{4}");
    //15861808327 手机号检测
    //regex reg("1\d{10}");
    //2018/4/9
    //regex reg("\d{4}/\d{2}/\d{2}");
    //?有没有都可以
    regex reg("^\d{4}/(0?[1-9]|1[0-2])/(0?[1-9]|[1-2][0-9]|3[0-1])$");
    while (true)
    {
        cout << "请输入日期" << endl;
        string str;
        if (!getline(cin, str) || str == "q")
        {
            break;
        }

        if (regex_match(str, reg))
        {
            cout << "OK" << endl;
        }
        else
        {
            cout << "NO" << endl;
        }
    }
    cin.get();
}

//挖掘匹配的字符串
void main2()
{
    //精确匹配
    //regex reg("1234");
    //匹配四个数字
    //regex reg("\d{4}");
    //15861808327 手机号检测
    //regex reg("1\d{10}");
    //2018/4/9
    //regex reg("\d{4}/\d{2}/\d{2}");

    regex reg("^\d{4}/([0]*?[1-9]|1[0-2])/([0]*?[1-9]|[1-2][0-9]|3[0-1])$");
    while (true)
    {
        cout << "请输入日期" << endl;
        string str;
        if (!getline(cin, str) || str == "q")
        {
            break;
        }

        smatch m;//进行检测与匹配
 63         if (regex_match(str, m, reg))
        {
            int year = atoi(m[0].str().c_str());
            int month = atoi(m[1].str().c_str());
            int day = atoi(m[2].str().c_str());
            cout << "year = " << year << endl;
            cout << "month = " << month << endl;
            cout << "day = " << day << endl;
            cout << "OK" << endl;
        }
        else
        {
            cout << "NO" << endl;
        }


        /*if (regex_match(str, reg))
        {
            cout << "OK" << endl;
        }
        else
        {
            cout << "NO" << endl;
        }*/
    }
    cin.get();
}

//正则表达式迭代挖掘数据
void main()
{
    setlocale(LC_ALL, "zh_CN");
    //精确匹配
    //regex reg("1234");
    //匹配四个数字
    //regex reg("\d{4}");
    //15861808327 手机号检测
    //regex reg("1\d{10}");
    //2018/4/9
    //regex reg("\d{4}/\d{2}/\d{2}");
    //匹配字母或数字或下划线或汉字
    regex reg("[\w]+");
    while (true)
    {
        cout << "请输入一串字符" << endl;
        string str;
        if (!getline(cin, str) || str == "q")
        {
            break;
        }
113         const sregex_iterator end;
114         for (sregex_iterator it(str.begin(), str.end(), reg); it != end; it++)
115         {
116             cout <<  (*it)[0] << endl;
117         }
    }
    cin.get();
}