Parsing URL query string in your web page (JavaScript)

This is a quick function I wrote that will parse out the query string name=value pairs and return an object with those names defined.  If no query parameters were supplied, the function returns undefined.

   1:  function getDocumentQueryVariables() {

   2:   

   3:      // Return undefined if there are no query variables

   4:      if (window.location.search.length == 0)

   5:          return undefined;

   6:      var objVars = {};

   7:      var vars = window.location.search.substring(1).split('&');

   8:      for (var i = 0; i < vars.length; i++) {

   9:          var pair = vars[i].split('=');

  10:          if(pair.length == 2) {

  11:              objVars[decodeURIComponent(pair[0])] = decodeURIComponent(pair[1]);

  12:          }

  13:      }

  14:      return objVars;

  15:  }

For example, you could have “?search=something” at the end of your web page.  This function will pass back an object with a property called “search” set to whatever value was supplied.

For example

   1:      // Exit if there's no query variable(s)

   2:      var Q = getDocumentQueryVariables();

   3:      if (Q === undefined)

   4:          return;

   5:   

   6:      // Perform search if we have one

   7:      if (Q.search) {

   8:          

   9:      }