如何在php中从字符串中分隔字母和数字

$str = "abc123def456";
$result = preg_split("/[^a-zA-Z0-9]+/", $str);
print_r($result);

Array
(
    [0] => abc
    [1] => 123
    [2] => def
    [3] => 456
)

$str = "abc123def456";
$characters = str_split($str);
$result = [];
$current = "";
foreach ($characters as $char) {
    if (ctype_alpha($char) && ctype_alpha($current)) {
        $current .= $char;
    } elseif (ctype_digit($char) && ctype_digit($current)) {
        $current .= $char;
    } else {
        if (!empty($current)) {
            $result[] = $current;
        }
        $current = $char;
    }
}
if (!empty($current)) {
    $result[] = $current;
}
print_r($result);

Array
(
    [0] => abc
    [1] => 123
    [2] => def
    [3] => 456
)