Online PHP editor | refs for TBTFj

<?php function array_map_via_callback($f, $a) { $o = []; $c = function ($v) use (&$o) { $o[] = $v; }; foreach ($a as $k => $v) $f($v, $c); return $o; } // Mapping $x => $x ^ 2 function forClassicMap($x) { return $x * $x; } $mapped1 = array_map('forClassicMap', [1, 2, 3]); // Mapping $x => $x ^ 2 via callback function forMapViaCallback($x, $callback) { $callback($x * $x); } $mapped2 = array_map_via_callback('forMapViaCallback', [1, 2, 3]); var_dump($mapped1, $mapped2);