php根据序号生成excel列号

function number_to_excel_column($num) {
    $result = '';
    while ($num > 0) {
        $mod = ($num - 1) % 26;
        $result = chr(65 + $mod). $result;
        $num = intval(($num - 1) / 26);
    }
    return $result;
}