Online PHP editor | refs for 2Y0q4

<?php $strings = [ 'A number at the end 1357', '2368 Letters and spaces 8675309', ]; foreach ($strings as $string) { var_export([ 'strcspn' => strcspn($string, 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ '), //reduces to 'a..zA..Z ' 'strspn' => strspn($string, 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ '), //reduces to 'a..zA..Z ' 'strpbrk' => strpbrk($string, 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ '), //reduces to 'a..zA..Z ' 'strtok' => strtok($string, 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ '), //reduces to 'a..zA..Z ' 'strtok2' => strtok('abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ '), //reduces to 'a..zA..Z ' ]); echo "\n--\n"; }