Regular expression to get facebook profile

Question

I tried to check matches facebook url and get profile in one regular expression: I have:

http://www.facebook.com/profile.php?id=123456789
https://facebook.com/someusername

I need:

123456789
someusername

using this regular expression:

(?<=(https?://(www.)?facebook.com/(profile.php?id=)?))([^/#?]+)

I get:

profile.php
someusername

Whats wrong?

Answer 1

I advise you to use the System.Uri class to get this information. It does the difficult work for you and can handle all sorts of edge cases.

var profileUri = new Uri(@"http://www.facebook.com/profile.php?id=123456789");
var usernameUri = new Uri(@"https://facebook.com/someusername");

Console.Out.WriteLine(profileUri.Query); // prints "?id=123456789"
Console.Out.WriteLine(usernameUri.AbsolutePath); // prints "/someusername"

Answer 2

I agree with others on using System.Uri but your regex needs two modifications to work:

• \ in (profile.php\?id=)

• (\n|$) at the end

  (?<=(https?://(www\.)?facebook\.com/(profile\.php\?id=)?))([^/#?]+)(\n|$)