placing a multi-dimensional array into Javascript from PHP using JSON - php

Question

My php script sends back a JSON encoded string.
I'm just lost on how to actually use the array now it sits nicely in Javascript?
The end goal is to loop through the the multi-dimensional array in JavaScript to extract values (prices)...
I've managed to get JavaScript to receive the encoded string (tested by printing it onto screen), but I'm not sure how I can actually use the array, or how I would loop through it like I would in PHP..
I basically need to do the JavaScript equivalent to this PHP code
foreach ($array as $item => $value){
foreach ($value as $item2 => $value2){
//peform action on $value2;
}
}
Thanks for any help.
Oz

Answer 1

Assuming you've called the variable arrayFromPhp, you can use a simple nested for loop:
for(var i = 0, l = arrayFromPhp.length; i < l; i++) {
for(var j = 0, l2 = arrayFromPhp[i].length; j < l2; j++) {
var value = arrayFromPhp[i][j];
//Do stuff with value
}
}

Answer 2

Using jquery, you can iterate on a json object like that:
$.each(obj, function(key, value) {
if ($.type(value) == "object") {
$.each(value, function(key, value) {
// value would be $value2 here
})
}
});
Also, if you get a json encoded string from PHP, you can use http://api.jquery.com/jQuery.parseJSON/ to get a json object
var obj = jQuery.parseJSON(stringFromPhp);
You can also directly use $.getJSON() (http://api.jquery.com/jQuery.getJSON/) to automatically get the json object in the callback.
edit: a parenthesis was missing.