How can I create js array from json object returned from php?

Question

Javascript has this fin line of code that alerts you what type of object you are working with. It is the following:

alert(Object.prototype.toString.apply(obj))

So, I am working with php and js - extjs 4.2, and looking for a way to pass an associative array created by php to java by using json_encode(). So I did the following:

<?php echo json_encode($some_array); ?>

Ext.Ajax.request(
{
    url: 'php/parse.php?id='+buttonText,
    method: 'GET',
    success: function(response) 
    {
        //var obj = response;
        var obj = response.responseText;
        alert(Object.prototype.toString.apply(obj));                    
    },
    failure: function(response) 
    {
        alert('server-side failure with status code ' + response.status);
    }
});

The php part of the code is in parse.php file as you can see from js code. When I alert the obj, it shows a string of json encoded php array. And js says that obj is a string object. If I keep the commented line without responseText, js alerts that obj is an Object but does not say what type (guessing json type).

What i am trying to achieve, is to have a legit js array that will get that php array from response (response is the param. in the function). Thanks

EDIT : my php array structure

array
(
    'vars' => array( 
                   [0] => 'name' => '1', 'value' => 2
                   [1] => ... )
    'file' => array(
                   [0] => 'name' => 'aaa.aa'
                   [1] => ...)
)

Answer 1

You're asking how to parse a string of JSON-encoded data into Javascript objects.

The built-in JSON.parse function does exactly that.