JavaScript: Parsing URL parameters

Submitted by dziemecki on Thu, 06/03/2010 - 14:09

Here's a nifty little JavaScript function that will read the URL of the the current page and return the value of a requested parameter:

// return a parameter value from the current URL
function getParam ( sname )
{
  var params = location.search.substr(location.search.indexOf("?")+1);
  var sval = "";
  params = params.split("&");
    // split param and value into individual pieces
    for (var i=0; i<params.length; i++)
       {
         temp = params[i].split("=");
         if ( [temp[0]] == sname ) { sval = temp[1]; }
       }
  return sval;
}

Given a URL something like "http://www.yoursite.com/app.asp?somevar=someval", you would call it like this:

function foo()
{
  var bar = getParam("somevar");
  alert(bar);
}

Merry scripting.
Tags: 
JavaScript

Comments

Submitted by Anonymous (not verified) on Thu, 06/13/2013 - 10:00.

Works fine! Thanks!

Submitted by Samual Wega (not verified) on Thu, 11/07/2013 - 13:33.

Thanks dear...u r really genious...

Submitted by Myles O'Brien (not verified) on Fri, 11/15/2013 - 03:36.

Does the trick very neatly!

Submitted by Anonymous (not verified) on Sat, 11/16/2013 - 09:17.

This doesn't handle when a query string doesn't have a value, it should then return `null`. It also doesn't handle `+` which means space.

See: https://github.com/sindresorhus/query-string

Submitted by Anonymous (not verified) on Sat, 02/22/2014 - 11:41.

Thanks................
:)

Submitted by Anonymous (not verified) on Mon, 09/29/2014 - 15:05.

So how would I go about printing the variable in an HTML form field as in this example:

Submitted by dziemecki on Tue, 09/30/2014 - 08:14.

You'd use the Document Object Model. Something like this:

oFormObject = document.forms['myform_id'];
oFormObject.elements["element_name"].value = getParam("somevar");

http://www.javascript-coder.com/javascript-form/javascript-form-value.phtml

Dan Ziemecki

Submitted by Michelle (not verified) on Tue, 11/04/2014 - 16:44.

Dan,

REAlly new to javascript.

I see this code of yours above:

Would you actually need to write two functions?

How would I get the value of ' bar ' into the input value of a field in a form?

For example here is the input line in the form:

I hope my questions are clear. %-)

Thank You,
Michelle

Submitted by dziemecki on Wed, 11/05/2014 - 08:16.

> Would you actually need to write two functions?

No. That just makes the first part reuasable. If you only need it to happen once, you can write it as one function.

> How would I get the value of ' bar ' into the input value of a field in a form?

Someone else asked about that, too. Look below at the comment titled "DOM".

Dan Ziemecki