Why does checking this string with Regex.IsMatch cause CPU to reach 100%?

Question

When using Regex.IsMatch (C#, .Net 4.5) on a specific string, the CPU reaches 100%.

String:

https://www.facebook.com/CashKingPirates/ph         


        

Answer 1

I suggest you to check http://regexr.com/ website, to test your regular expression.

The corrected version of your regular expression is this:

^(https?://(?:[\w]+\.?[\w]+)+[\w]/?)([\w\./]+)(\?[\w-=&%]+)?$

It also has 3 groups:

1. group1=Main url (for example: facebook.com)
2. group2=Sub urls (for example: /CashKingPirates/photos/a.197028616990372.62904.196982426994991/1186500984709792/
3. group3=Variables (for example: ?type=1&permPage=1)

Also remember for checking actual character of dot (.) in your regular expression you must use \. not .