Online PHP editor | refs for pMZ5N

<?php $array = [ [ 'key_1' => 'FOO', 'key_2' => 'FTU-1', 'cats' => '/30/' ], [ 'key_1' => 'FOO', 'key_2' => 'FTU-2', 'cats' => '/30/' ], [ 'key_1' => 'FOO', 'key_2' => 'FTU-3', 'cats' => '/30/10/' ], [ 'key_1' => 'FOO', 'key_2' => 'FTU-4', 'cats' => '/15/' ], [ 'key_1' => 'FOO', 'key_2' => 'FTU-5', 'cats' => '/10/' ], [ 'key_1' => 'FOO', 'key_2' => 'FTU-6', 'cats' => '/15/' ], ]; $result = []; foreach ($array as $row) { $cats = preg_split('#/#', $row['cats'], 0, PREG_SPLIT_NO_EMPTY); foreach ($cats as $cat) { $result[$cat][] = $row; } } var_export($result);