Best way to count hyperlinks in textarea using Javascript client-side?

Question

We have a textarea control that holds text and hyperlinks. The links are stored as follows:

http://www.google.com [Link to a site __title__ Title of Link]
http://www.yahoo.com [http://www.yahoo.com __title__ Link with text & hyperlink the same]

In the second link, I don't want to count yahoo twice, so I want to ignore links starting with the left bracket. I know that using Regex to do this isn't the best way, but I don't know of any other way to accomplish this. So far I've tried this regex, but I figured out that Javascript doesn't support lookbehind:

(?<!\[)((http|https|ftp)\://(www\.)?)(([a-zA-Z0-9\.-]+\.[a-zA-Z]{2,4})|([0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}))(/[a-zA-Z0-9%:/_\?\.'~&=-]*)

Anyone know of a decent way to accomplish this?

I just found out also that I can't rely on the brackets. Users can enter any type of link, using our tool that creates the brackets or by just entering it manually themselves.

Answer 1

Count the number of the character [ in the textarea contents.
The above solution will work, if the format that you have mentioned above persists.

Answer 2

You just need a count? Can't you count all the links then count all the links starting with the left bracket, and subtract?