Online PHP editor | refs for 6eAMe

<?php declare(strict_types = 1); $map = [ 1 => 'foo', 2 => 'foo', 3 => 'bar', ]; $names = ['foo', 'bar', 'baz']; $array = ['foo' => [], 'bar' => [], 'baz' => []]; foreach ($map as $value => $name) { $array[$name][] = $value; } foreach ($array as $name => $elements) { echo sprintf('"%s" -> "%d".' . PHP_EOL, $name, count($elements) > 0); }