declare(strict_types=1); <html><body>function test_odd(int $var) { return($var & 1); }$a1=array(1,3,2,3,4);print_r(array_filter($a1,"test_odd"));</body><!-- Mirrored from www.w3schools.com/php/phptryit.asp?filename=tryphp_func_array_filter by HTTrack Website Copier/3.x [XR&CO'2014], Mon, 27 Jan 2020 02:50:52 GMT --></html>