对于数组的第三个元素，is_file函数总是返回false

This is a simple PHP function to clean all the empty folders in a directory.

But it always takes the third element of the array as a directory, even if it's a file.

function myfunction($s){
    echo "<br>Now the directory is $s";
    echo "<br>";
    if (is_file($s)) {
        echo "$s is a file <br>";
        return;
    }
    else {
        echo "$s is a directory";
        chdir($s);
        $d = scandir(".");
        echo "<br> Array elements are ". print_r($d) . "<br>";
        echo sizeof($d);
        for ($i= 2; $i <sizeof($d); $i++) {
            $a = $d[$i];
            echo "<br>Now the folder is $a <br>";
            echo "<br>";
            if (empty($a)) {
                rmdir($a);
            }
            else{
                myfunction($a);
                chdir("..");
            }
        }
    }
}

The function empty() does no test a directory's content for emptiness, but only if the value of a variable is empty. Your variable $a contains the file name of the current iteration, so you are testing whether or not a file has a file name. That will never happen, so you are always executing the branch with the recursive call.

You basically need to count the number of entries scandir() returns for a directory. If the conut is 2, the directory is empty and can be removed.