Online PHP editor | output for abW9q

<?php $allOptions = [ ["clID" => 171], ["clID" => 191], ["clID" => 131], ["clID" => 101], ["clID" => 201], ["clID" => 181], ["clID" => 99], // not in regOptions ["clID" => 129], // not in regOptions ["clID" => 139], ]; $regOptions = [ ["order" => 1, "optID" => 131], ["order" => 2, "optID" => 191], ["order" => 3, "optID" => 181], ["order" => 4, "optID" => 139], ["order" => 5, "optID" => 101], ["order" => 6, "optID" => 201], ["order" => 7, "optID" => 171], ]; $priority = array_column($regOptions, 'order', 'optID'); usort( $allOptions, fn($a, $b) => ($priority[$a['clID']] ?? PHP_INT_MAX) <=> ($priority[$b['clID']] ?? PHP_INT_MAX) ); var_export($allOptions);