using System;
using System.Text.RegularExpressions;
public class Example
{
public static void Main()
{
string pattern = @"^(?=.{5,12}$)(?=(?:[^a-zA-Z\u0590-\u05fe\n]*[a-zA-Z\u0590-\u05fe]){4}[^a-zA-Z\u0590-\u05fe\n]*$)[a-zA-Z\u0590-\u05fe]{0,4}[0-9]{3,8}[a-zA-Z\u0590-\u05fe]{0,4}$";
string input = @"abcd123efgh
abc123efgh
abc123efg
ab123efg
ab123ef
a123ef
a123e
ab123c
abc123d
123abcd
123e
123e";
RegexOptions options = RegexOptions.Multiline;
foreach (Match m in Regex.Matches(input, pattern, options))
{
Console.WriteLine("'{0}' found at index {1}.", m.Value, m.Index);
}
}
}
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for C#, please visit: https://msdn.microsoft.com/en-us/library/system.text.regularexpressions.regex(v=vs.110).aspx