From the December 2015 Issue of Prestwood eMag

Coder General .Net Concepts: Regex By Bryan Valencia

Posted 14 years ago on 10/6/2008 and updated 11/7/2008 Take Away: Console application shows some common uses of Regular Expressions (REGEX) to match and recursively replace text in strings.  Tags: Regex , C# , Regular Expressions KB101321

This console application shows some common uses of Regular Expressions (REGEX) to match and recursively replace text in strings.

This is very fast compared to loop compares and very powerful if you know how to use them.

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

namespace Regexes
{
class Program
{

static void testMatch(string pattern, string s)
{
if (Regex.IsMatch(s,pattern) ){
Console.WriteLine(string.Format("MATCH {0,-20}",s));
} else {
Console.WriteLine(string.Format("NO MATCH {0,-20}",s));
}
}

static void Convert(string pattern, string s)
{
Console.WriteLine("{0,-20} becomes {1,-20}",s,Regex.Replace(s, pattern, string.Empty));
}

static void Main(string[] args)
{

Console.WriteLine("\n\n---\nValidate that the input is one of the 50 US States\n---");
string StatePattern = @"(:?A[KLRZ]|C[AOT]|D[CE]|FL|GA|HI|I[ADLN]|K[SY]|LA|M[ADEINOST]|N[CDEHJMVY]|O[HKR]|P[AR]|RI|S[CD]|T[NX]|UT|V[AIT]|W[AIVY])";

testMatch(StatePattern, "California");
testMatch(StatePattern, "CA");
testMatch(StatePattern, "AS");
testMatch(StatePattern, "JP");
testMatch(StatePattern, "MS");
testMatch(StatePattern, "AZ and HI");

Console.WriteLine("\n\n---\nremove HTML markup\n---");
string HTMLPattern = @"<(.|\n)*?>";
Convert(HTMLPattern, "Plain Text");

Convert(HTMLPattern, "<p>a Paragraph</p>");
Convert(HTMLPattern, "a Photo <img src=\"http://site.com/photo.jpg\" />");

Console.WriteLine("\n\n---\njpg, gif or png (or adjust to accept any kind of file.)\n---");
string ImgPattern=@"([^\s]+(?=\.(jpg|gif|png))\.\2)";
testMatch(ImgPattern, @"C:\my documents\photo.jpg");
testMatch(ImgPattern, @"Program.exe");
testMatch(ImgPattern, @"WrongKind.bmp");

Console.WriteLine("\n\n");
}
}
}

Console application shows some common uses of Regular Expressions (REGEX) to match and recursively replace text in strings. This console application demonstrates some common uses.

More Info

KB Post:

Regular Expressions Cheat Sheet

PS_2880

Comment 1 of 1 THis Code was updated 12 Years ago & it‘s still useful. Thanks Bapubsk Tips Posted 24 months ago

KB Post Contributed By Bryan Valencia:

Bryan Valencia is the author of millions of lines of code and writes for PrestwoodBoards and Visual Studio Journey on-line magazines. Visit Profile