TA, C# - Part2, Strings and Text Processing, #18

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Text.RegularExpressions;

/* #18. Write a program for extracting all email addresses from given text. All substrings that match the format <identifier>@<host>…<domain> should be recognized as emails. */

class ExtractEMailAddresses
{
    static void Main()
    {
        Console.WriteLine("Please enter a text below:");
        string inputText = Console.ReadLine();

        string[] arrayOfExpressions = inputText.Split(' ');
        Console.WriteLine("The e-mail addresses are:");
        for (int i = 0; i < arrayOfExpressions.Length; i++)
        {
            if (Regex.IsMatch(arrayOfExpressions[i], @"[\w., \-]{2,20}@[\w., \-]{2,20}[.]{1}[\w.]{2,6}"))
            {
                // Remove '.', '?', '!', ';' or "-" signs at the end
                if (arrayOfExpressions[i][arrayOfExpressions[i].Length - 1] == '.' || arrayOfExpressions[i][arrayOfExpressions[i].Length - 1] == '?' || arrayOfExpressions[i][arrayOfExpressions[i].Length - 1] == '!' || arrayOfExpressions[i][arrayOfExpressions[i].Length - 1] == ';' || arrayOfExpressions[i][arrayOfExpressions[i].Length - 1] == '-')
                { arrayOfExpressions[i] = arrayOfExpressions[i].Remove(arrayOfExpressions[i].Length-1, 1); }
                Console.WriteLine("{0}", arrayOfExpressions[i]);
            }
        }
    }
}