How to sort a string with digits and letters (letters before digits) in PHP

1 Answer

0 votes
function customSort($input) {
    $chars = str_split($input);

    usort($chars, function ($a, $b) {
        if (ctype_alpha($a) && ctype_digit($b)) return -1;
        if (ctype_digit($a) && ctype_alpha($b)) return 1;
        return strcmp($a, $b);
    });

    return implode('', $chars);
}

$input = "d2c4b3a1";
$sortedInput = customSort($input);

echo "Custom sorted string: $sortedInput\n";



/*
run:

Custom sorted string: abcd1234

*/

 



answered May 26, 2025 by avibootz
edited May 27, 2025 by avibootz
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