How to implement something like PHP's http_build_query and the reverse in javascript?

Question

<?php
$data = array('foo'=>'bar',
              'baz'=>'boom',
              'cow'=>'milk',
              'php'=>'hypertext processor');

echo http_build_query($data);
/* Output：
      foo=bar&baz=boom&cow=milk&php=hypertext+processor
*/

How to do similar thing in javascript,say, get the query string from the array ,and convert the array to query string?

UPDATE

the jquery plugin is not working:

var fromVar = $.query.load('?cow=milk')
fromVar.set('first', 'value'); 
fromVar.toString()

It outputs ?cow=milk while I want it to be ?cow=milk&first=value

Answer 1

Try the jQuery query plugin. It's pretty intuitive. You can use get and set accessors to read and modify the query string:

var cow = $.query.get('cow');
$.query.set('cow', 'goat');

You can create a new query object from an existing string:

var fromVar = $.query.load('?cow=milk')
var cow = fromVar.get('cow'); // milk

You can also create an empty object:

var newQ = $.query.empty();
newQ = newQ.set('first', 'value'); // "?first=value"

Answer 2

If you're using jQuery, then you can use the jQuery.param() function:

var array = { "foo":"bar", "baz":"boom", "php":"hypertext processor" };
var str = jQuery.param(array);
alert(str); // should be "foo=bar&baz=boom&php=hypertext+processor"

It can serialise some complex arrays too.