javascript strip words from url

i got a little book marklet

javascript:window.location='http://alexa.com/siteinfo/'+window.location.host;

when clicked it takes you to alexa.com/siteinfo/www.thesiteyouwereon.com

i dont know a lot about js regex..is there a way to get rid of the www. from the begining of the sit开发者_Python百科e. so i can get alexa.com/siteinfo/nowwwsite.com

thanks for the help..sorry if this was stupid q.

Just remove www: String(window.location.host).replace(/^www\./,'')

Remove http, https, and www: String(window.location.host).replace(/^(https?:\/\/)?(www\.)?/,'')

Regex is really worth learning. Really.

Explanation of regex:

• ^ means at the start of the input (either line, or string depending on the m modifier). And $ means at the end.
• ? means optional, or if used with * or + means least
• * means zero or more
• + means one or more
• . means any character, so if you want jut a dot, then use \. as it must be escaped.
• [a-z0-9_] means any a to z, 0 to 9, and a underscore character.
• [^a-z] means anything that is not a to z character.
• () surrounds a group
• $1 references the first group