An easy way to parse the query string in your URL to grab certain values.
Get URL Parameters Using Javascript
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.foo.com/index.html?bob=123&frank=321&tom=213#top
You want to get the value from the frank parameter so you call the javascript function as follows:
var frank_param = gup( ‘frank’ );
Now if you look at the frank_param variable it contains the number 321. The query string was parsed by the regular expression and the value of the frank parameter was retrieved. The function is smart in a couple of ways. For example, if you have an anchor in your URL like our example URL above does (#top) the gup() function knows to stop before the # character. Also, if a requested parameter doesn’t exist in the query string then an empty string is returned instead of a null.
This function has worked very well for my query string parsing needs and should work well for you.
url source: http://www.netlobo.com/url_query_string_javascript.html
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