So, using JavaScript I have a parser for a URL:    function parseUrl(url) {       var e = /((http|https|ftp):\/\/)?((.*?)\/)?((.*)\/)?(.*)?/;       if (url.match(e)) {          return  { url:     ...

Regex to strip everything except <h3>, <h4> and <h5> tags and the text within these tags Platform: javascript Input: <div><p>Some text</p><h3><a href ="#">link text here</a></h3></div> Output: <h3>link text here</h3>

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 ...

This has been driving me crazy all day. Is there any way to match newlines or linebreaks in a textarea html element.  I am not talking about when a user adds a line break by hitting enter for example.  I am talking about when the browser automatically returns a newline or wraps the line.  These breaks need to be matched via ...

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 ...