3v4l.org

run code in 300+ PHP versions simultaneously
<?php $input = ['1, 2, 3, 4, 5', 'test', 3, '100, a, test']; foreach ($input as $item) { if (is_string($item)) { foreach (explode(',', $item) as $i) { if (is_numeric($i)) { echo trim($i) . PHP_EOL; } } } }

preferences:
23.46 ms | 406 KiB | 5 Q