From: Timothy Hunter <TimHunter@...>
Date: 2006-08-25T09:18:38+09:00
Subject: Re: Determinig if 3 characters in a row are the same?

Ben Johnson wrote:
> Sorry for the noob question, but is there a fast and efficient way to 
> determine if there are 3 of the same charater in a row in a string? I'm 
> sure this could be done in regex but I am not a black belt in regex.
>
> thanks for your help.
>
>   
If by "character" you mean any character then this will do the trick:

irb(main):004:0> m = /(.)\1\1/.match('zyzyzxxx010101')
=> #<MatchData:0x1743d78>
irb(main):005:0> m[0]
=> "xxx"
irb(main):006:0> m = /(.)\1\1/.match('zyzyzxyx010101')
=> nil

If you meant "alphabetic character" or "alpha-numeric character" then it 
needs a bit of tweaking.