Sorting an array of directory filenames in descending natural order

Question

I have a content directory to be returned in descending natural order.

I\'m using scandir() and natsort(), but the addition of array_reve

Answer 1

If your image names will be in the format 123-image_name.jpg, 2323-image_name.jpg, ... this will do:

/**
 * Compares digits in image names in the format "123-image_name.jpg"
 *
 * @param string $img1 First image name
 * @param string $img2 Second image name
 * @return integer -1 If first image name digit is greater than second one.
 * 0 If image name digits are equal.
 * 1 If first image name digit is smaller than second one.
 */
function compareImageNames($img1, $img2){
    $ptr = '/^(\d+)-/'; // pattern

    // let's get the number out of the image names
    if (preg_match($ptr, $img1, $m1) && preg_match($ptr, $img2, $m2)) {
        $first  = (int) $m1[0]; // first match integer
        $second = (int) $m2[0]; // second match integer

        // equal don't change places
        if($first === $second) return 0;

        // if move first down if it is lower than second
        return ($first < $second) ? 1 : -1;
    } else{
        // image names didn't have a digit in them
        // move them to front
        return 1;
    }
}

// sort array
usort($images, 'compareImageNames');