using System;
using System.Text.RegularExpressions;
public class Example
{
public static void Main()
{
string pattern = @"^(?:(?:1[6-9]|[2-9]\d)?\d{2})(?:(?:(\/|-|\.)(?:0?[13578]|1[02])\1(?:31))|(?:(\/|-|\.)(?:0?[13-9]|1[0-2])\2(?:29|30)))$|
^(?:(?:(?:1[6-9]|[2-9]\d)?(?:0[48]|[2468][048]|[13579][26])|(?:(?:16|[2468][048]|[3579][26])00)))(\/|-|\.)0?2\3(?:29)$|
^(?:(?:1[6-9]|[2-9]\d)?\d{2})(\/|-|\.)(?:(?:0?[1-9])|(?:1[0-2]))\4(?:0?[1-9]|1\d|2[0-8])$";
string input = @"2020-01-31
1989-3-31
1989-01-30
2020-03-29
2020-02-29
2020-2-29
2017-04-09
2021-05-31
2021
jnnij
14
";
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