- ctype_alpha: documentation ( source)
- strtolower: documentation ( source)
<?php
function returnFirst($rsrnum) {
$char = $rsrnum[0];
return ctype_alpha($char) ? strtolower($char) : '%23';
}
echo returnFirst('ADSASTEADS')."\n";
echo returnFirst(2342342)."\n";
echo returnFirst('3SASDAsd')."\n";