php字母转成数字,php字母和数字互转。
function charToNum($string) {
$char = 'abcdefghijklmnopqrstuvwxyz';
$char = chunk_split($char, 1, ',');
$char = explode(',', $char);
return is_numeric($string) ? $char[$string] : array_flip($char)[$string];
}