- var_dump: documentation ( source)
- preg_match: documentation ( source)
<?php
function cele_cislo($cislo) {
return preg_match('/^[1-9]\d*$/', $cislo) === 1;
}
var_dump(cele_cislo('123456f'));
var_dump(cele_cislo('f123456'));
var_dump(cele_cislo('123456'));