Regex_mixed_groups_test

using System;
using System.Text.RegularExpressions;

namespace _07._Vending_Machine
{
    class Program
    {
        static void Main(string[] args)
        {
            var regex = new Regex(@"\b(?<month>[A-Z][a-z]{2})([-.\/])(?<day>\d{2})\1(?<year>\d{4})_([a-z]+)_(?<someOtherGroup>[0-9]+)_([0-9]+)+\b");


            string dates = "Apr.16.2017_jan_07_2019"; //Console.ReadLine();

            var matches = regex.Matches(dates);

            foreach (Match item in matches)
            {
                var separator = item.Groups[1].Value; // = ([-.\/])// result: .
                var secondMonth = item.Groups[2].Value; // = ([a-z]+)// result: jan
                var secondYear = item.Groups[3].Value; // = ([-.\/])// result: 2019
                var month = item.Groups[4].Value; // = item.Groups["month"].Value;// result: Apr
                var day = item.Groups[5].Value; // = item.Groups["day"].Value; // result: 16
                var year = item.Groups[6].Value; // = item.Groups["year"].Value; // result: 2017
                var someOtherGroup = item.Groups[7].Value; // = item.Groups["someOtherGroup"].Value; // result: 07

                Console.WriteLine(separator);
                Console.WriteLine(secondMonth);
                Console.WriteLine(secondYear);
                Console.WriteLine(month);
                Console.WriteLine(day);
                Console.WriteLine(year);
                Console.WriteLine(someOtherGroup);
            }
        }
    }
}