Javascript regex to find a base URL

Question

I\'m going mad with this regex in JS:

var patt1=/^http(s)?:\\/\\/[a-z0-9-]+(.[a-z0-9-]+)*?(:[0-9]+)?(\\/)?$/i;

If I give an input string like \

Answer 1

I'm no javascript pro, but accustomed to perl regexp, so I'll give it a try; the . in the middle of the regexp might need to be escaped, as it can map a / and jinx the whole regexp.

Try this way:

var patt1=/^http(s)?:\/\/[a-z0-9-]+(\.[a-z0-9-]+)*?(:[0-9]+)?(\/)?$/i; 

Answer 2

Considering you have a properly formatted URL this simple RegExp should do the trick every time.

var patt1=/^https?:\/\/[^\/]+/i;

Here's the breakdown...

Starting with the first position (denoted by ^)

Look for http

http can be followed by s (denoted by the ? which means 0 or 1 of the character or set before it)

Then look for :// after the http or https (denoted by :\/\/)

Next match any number of characters except for / (denoted by [^\/]+ - the + means 1 or more)

Case insensitive (denoted by i)

NOTE: this will also pick up ports http://example.com:80 - to get rid of the :80 (or a colon followed by any port number) simply add a : to the negated character class [^\/:] for example.