An easy way to parse the query string in your URL to grab certain values.

Most of the server-side programming languages that I know of like PHP, ASP, or JSP give you easy access to parameters in the query string of a URL. Javascript does not give you easy access. With javascript you must write your own function to parse the window.location.href value to get the query string parameters you want. Here is a small function I wrote that will parse the window.location.href value and return the value for the parameter you specify. It does this using javascript's built in regular expressions. Here is the function:

 
 
function gup( name )
{
  name = name.replace(/[[]/,"\\\[").replace(/[]]/,"\\\]");
  var regexS = "[\\?&]"+name+"=([^&#]*)";
  var regex = new RegExp( regexS );
  var results = regex.exec( window.location.href );
  if( results == null )
    return "";
  else
    return results[1];
}
 

The way that the function is used is fairly simple. Let's say you have the following URL:

http://www.jiawebdesign.com/dev/get-url-parameters.html?cp=testing

The value of the variable cp is equal to testing in this example.

This article source from here.