How to extract the host from a URL in JavaScript?

If you actually have valid URLs, this will work:

var urls = [    'http://domain.com:3000',    'http://domain.com?pass=gas',    'http://domain.com/',    'http://domain.com'];for (x in urls) {    var a = document.createElement('a');    a.href = urls[x];    console.log(a.hostname);}//=> domain.com//=> domain.com//=> domain.com//=> domain.com

Note, using regex for this kind of thing is silly when the language you're using has other built-in methods.

Other properties available on A elements.

var a = document.createElement('a');a.href = "http://domain.com:3000/path/to/something?query=string#fragment"a.protocol   //=> http:a.hostname   //=> domain.coma.port       //=> 3000a.pathname   //=> /path/to/somethinga.search     //=> ?query=stringa.hash       //=> #fragmenta.host       //=> domain.com:3000

EDIT #2

Upon further consideration, I looked into the Node.js docs and found this little gem: url#parse

The code above can be rewritten as:

var url = require('url');var urls = [    'http://domain.com:3000',    'http://domain.com?pass=gas',    'http://domain.com/',    'http://domain.com'];for (x in urls) {    console.log(url.parse(urls[x]).hostname);}//=> domain.com//=> domain.com//=> domain.com//=> domain.com

EDIT #1

See the revision history of this post if you'd like to see how to solve this problem using jsdom and nodejs

Since you're using node, just use the built-in url.parse() method; you want the resulting hostname property:

var url=require('url');var urls = [  'http://domain.com:3000',  'http://domain.com?pass=gas',  'http://domain.com/',  'http://domain.com'];

UPDATED:

urls.forEach(function(x) {  console.log(url.parse(x).hostname);});

A new challenger has appeared. According to node docs, you can also use

   var url = new URL(urlString);   console.log(url.hostname);

https://nodejs.org/api/url.html#url_the_whatwg_url_api

This seems to be a more current way.