json array sort by value in php - php

Question

I have JSON arrays of objects. I am trying to sort an array using usort. I want to use value field from field_listing_order. It sorted using value. I am missing something but not able to figure it out. please review the code. Thanks!
stdClass Object
(
[node_title] => abc
[nid] => 2281
[field_api_order_value] => 201
[field_node_entity_type] => node
[_data] => Array
(
[nid] => Array
(
[entity_type] => node
[entity] => stdClass Object
(
[title] => abc
[field_listing_order] => Array
(
[und] => Array
(
[0] => Array
(
[value] => 8
[format] =>
[safe_value] => 8
)
)
)
)
)
)
)
stdClass Object
(
[node_title] => abc
[nid] => 2243
[field_api_order_value] => 204
[field_node_entity_type] => node
[_data] => Array
(
[nid] => Array
(
[entity_type] => node
[entity] => stdClass Object
(
[title] => abc
[field_listing_order] => Array
(
[und] => Array
(
[0] => Array
(
[value] => 3
[format] =>
[safe_value] => 3
)
)
)
)
)
)
) stdClass Object
(
[node_title] => abc
[nid] => 2431
[field_api_order_value] => 242
[field_node_entity_type] => node
[_data] => Array
(
[nid] => Array
(
[entity_type] => node
[entity] => stdClass Object
(
[title] => abc
[field_listing_order] => Array
(
[und] => Array
(
[0] => Array
(
[value] => 1
[format] =>
[safe_value] => 1
)
)
)
)
)
)
)
and So on ...
foreach ($view->result as $result) {
$node = $result->_data['nid']['entity'];
$listing_order = $node->field_listing_order[LANGUAGE_NONE][0];
.....
// code goes here and it works well. sorting issue
}
usort ($node->field_listing_order[LANGUAGE_NONE][0], function($a, $b){
return strcmp($a->value, $b->value);
}); ?>

Answer 1

If you need to sort all the nodes using the field_listing_order value, you need to compare the values along the full path, from the first object to the value:
usort($view->result, function($a, $b) {
$la = $a->_data['nid']['entity']->field_listing_order[LANGUAGE_NONE][0]['value'];
$lb = $b->_data['nid']['entity']->field_listing_order[LANGUAGE_NONE][0]['value'];
return $la - $lb ;
});
In this case $a and $b are two different nodes which could be compared. That why you should compare the field_listing_order's value of these nodes. The answer is working with $la- $lb