Why is exclamation used in urls?

Question

Possible duplicate:
What is shebang (#!) On Facebook and the new Twitter URLs for?

Hi

I'm just wondering what a "!" in such urls

http://www.facebook.com/profile.php?id=xxxxxxxx&v=wall#!/profile.php?id=yyyyyy&v=wall

I know that Facebook uses # (hash) to change the query string parameters using JavaScript, but what is the point of exclamation ( ! ), Why is it used after #? We can even work with C # only to change querystring parameters. Is there any use to it !? or any other thing I'm missing?

Answer 1

This is because it is AJAX for URL encoding , Google’s efforts to define an agreement that allows websites to be indexed by search engines .

And of course, check out the reliable answer. What is Shebang in the new Facebook and Twitter URLs?

Answer 2

This is the convention used for AJAX requests, one that allows Google to crawl this ajax content . There are other basic examples of this, like twitter.

In Chrome (and other browsers as they are supported) you won’t see these URLs, since facebook also uses some HTML5 history features to change the URL in the address bar / browser history.