Create a gist now

Instantly share code, notes, and snippets.

What would you like to do?
get query variable

use like this:

getQueryVariable("foo")

To get variables in urls eg:

http://foo.com/index.html?foo=bar

If you want to support arrays, check the version by @atk below:

function(a){
return RegExp("[&?]"+a+"=([^&]+)").exec(location)[1]
}
//searches the url (location)
//finds the text after a "&" or a "?" followed by the variable name, followed by a "="
//and before another "&"
function(a){return RegExp("[&?]"+a+"=([^&]+)").exec(location)[1]}
//If you want to support arrays (Thanks atk!)
function(a){for(var b=[],c,d=eval('/[&?]'+a+'(\\[])?=([^&]+)/g');c=d.exec(location);)b.push(c[2]);return b}
{
"name": "getQueryVariable",
"description": "Get variables in urls",
"keywords": [
"url",
"query",
"string",
"variable",
"get"
]
}
<script>
getQueryVariable = function(a){return RegExp("[&?]"+a+"=([^&]+)").exec(location)[1]}
document.write(getQueryVariable("foo"))
</script>

atk commented May 15, 2012

&|\\? will not work properly, as it will match either "&" or "?[identifier=]", therefore returning the whole [identifier]=[value] string if it is preceded by "&". A working version would be:

function(a){return(RegExp('[&?]'+a+'=([^&;]+)').exec(location)||0)[1]}

Owner

williammalo commented May 15, 2012

@atk
Wow! I made a stupid mistake there =P
That code is very smart!
I didn't know that exec can reference stuff in parentheses! What a noob I am!

atk commented May 15, 2012

@williammalo: we live and learn :-)

tsaniel commented May 16, 2012

What about using split with regex?

atk commented May 16, 2012

The original code did, but exec is much smaller.

What about supporting array values (e.g. x[]=1&x[]=2)?

Owner

williammalo commented May 18, 2012

@FarSeeing
I'm sorry but I have no idea what you mean by that.

@williammalo
The current version throws an error, if you try to search for array parameters:

// location = 'http://example.com?a=1&b[]=2&b[]=3'
getQueryVariable = function(a){return RegExp("[&?]"+a+"=([^&]+)").exec(location)[1]}
getQueryVariable( 'a' ); // "1", correct
getQueryVariable( 'b' ); // TypeError: RegExp("[&?]" + a + "=([^&]+)").exec(txt) is null
getQueryVariable( 'b[]' ); // TypeError: RegExp("[&?]" + a + "=([^&]+)").exec(txt) is null

tsaniel commented May 21, 2012

A version which supports array:
function(a,b,c){with(eval('/[&?]'+a+'(\\[])?=([^&]+)/g'))for(b=[];c=exec(location);)b.push(c[2]);return b}

atk commented May 21, 2012

Those TypeErrors can be caught with a (...||0)[1] construct as in my proposal.

Owner

williammalo commented May 21, 2012

@tsaniel
If you can make a version without "with" I'll update my function. (I have withophobia)

atk commented May 22, 2012

Only 1 char longer:
function(a){for(var b=[],c,d=eval('/[&?]'+a+'(\\[])?=([^&]+)/g');c=d.exec(location);)b.push(c[2]);return b}

Owner

williammalo commented May 22, 2012

@atk
Great! it works perfectly! (I think...)
I'll put it in my gist!
Thanks!

onhate commented Nov 20, 2013

If you have an anchor on url like param=value#anchor it returns the value like value#anchor, you just need to add one more byte to the code to works =D

function url(a){for(var b=[],c,d=eval('/[&?]'+a+'([])?=([^&^#]+)/g');c=d.exec(location);)b.push(c[2]);return b}

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment