Online PHP editor | refs for nY7ZW

<?php $comments='[ { "user": "5", "points": "12" }, { "user": "2", "points": "1" }, { "user": "3", "points": "1" } ]'; $likes='[ { "user": "1", "points": 7 }, { "user": "4", "points": 4 }, { "user": "3", "points": 1 } ]'; $posts='[ { "user": "1", "points": "6" }, { "user": "3", "points": "2" }, { "user": "2", "points": "1" } ]'; $merged = array_merge(json_decode($comments, true), json_decode($likes, true), json_decode($posts, true)); $result = []; foreach ($merged as $entry) { if (!isset($result[$entry['user']])) { $result[$entry['user']] = $entry; } else { $result[$entry['user']]['points'] += $entry['points']; } } array_multisort(array_column($result, 'user'), $result); //usort($result, function($a, $b) { return $a['user']<=>$b['user']; }); // this is the most modern style, change if too advanced for your php version echo json_encode($result);