I ran into an interesting situation where back references overwrite previous changes in a regular expression. I needed a regular expression that updated a pattern but also checked for something that comes before the pattern.  It should leave everything before the pattern as it was before the updates.  There can be multiple matches of ...

The problem is with the way you are looking. When you check the character before the , you are telling the regular expression to include it. Use this expression which has a lookbehind expression in it. It will check the character before the comma and not include it in the match. (?<=[^\\]), I hope that helps, Brendan 

First I will let you know, that you should give a better description of what you want. Do you need to know how to do the javascript or the regex or both?  Should a single letter be a match? I assume that you need at least 2 values for it to be a match, and I am also just guessing that when you say single spaces you will allow more than one ...