- print_r: documentation ( source)
<?php
$arrays = [
[
"id" => 1,
"order_id" => 1,
"image_url" => "/resources/filename1"
],
[
"id" => 2,
"order_id" => 1,
"image_url" => "/resources/filename2"
]
];
foreach($arrays as $array) {
$result[$array['order_id']][]=$array['image_url'];
}
print_r($result);