As the complement of getting the domain name out of a URL and get domain name from URL using javascript, here is another way to get domain name using javascript.
If you are running a script in a website you can find out the domain name of the website by using document.domain property.
var mydomain=document.domain;

Here is a small function that will parse the window.location.href value and return the value for the parameter you specify.
<script type=”text/javascript”>
function get_url_parameter( param ){
param = param.replace(/[\[]/,”\\\[").replace(/[\]]/,”\\\]”);
var r1 = “[\\?&]“+param+”=([^&#]*)”;
var r2 = new RegExp( r1 );
var r3 = r2.exec( window.location.href );
if( r3 == null )??? return “”;
else??? return r3[1];
}
</script>
Suppose you have the following URL:
http://www.domain.com/index.html?test=123
And you want [...]

We can find out the domain name from URL by using location.hostname property.
var mydomain=window.location.hostname;
or we can also use location.href property but it’s a little harder.
var mydomain=window.location.href.match(/:\/\/(.[^/]+)/)[1];
The hostname property can be set to redirect location, but it is safer to set the href property.