PHP - Sort array of images by height

Question

Taking the following;

// Looping through images passed to function...

list($width[$i], $height[$i]) = getimagesize($img_urls[$i]);

// ... Now to reorder by height

How can I reorder the $height array to tallest > shortest, while maintaining the key relationship with the correct $width value?

I've attempted with uasort, but I've had no luck. The "closest" attempt I've had is below, but that sorts from smallest to largest

uasort($height, function($a, $b) use ($i) {
    return $a[$i] + $b[$i];
});

PLease code your sorting attempts so that we can see what your problem is. `uasort` is the way to go... — arkascha, May 03 '14 at 20:58

Sharikov Vladislav · Accepted Answer · 2014-05-03T21:10:52.063

Firstly, use structures:

class Image {
    public $width;
    public $height;
}

This is neccessary because width and heights of the image are hardly connected. Width of one image shows nothing without height of image. Same for height. You should link this data. For example, in structure.

After that, get images heights and widths:

$images = array();

// get widths and heights
loop start
    $img = new Image();
    $img->width = assign width;
    $img->height = assign height;
    $images[] = $img;
loop end

Finally, sort:

function cmp($a, $b) {
    if ($a->height == $b->height) {
        return 0;
    }
    return ($a->height < $b->height) ? -1 : 1;
}

uasort($images, 'cmp');

//$images are sorted by height now

Let me know if something is unclear.

score 0 · Answer 2 · answered May 03 '14 at 21:10

Try this:

$images = array();
for ($i = 0; $i < count($img_urls); $i++) {
    $image_size = getimagesize($img_urls[$i]);
    $images[$image_size[1]]['width'] = $image_size[0];
    $images[$image_size[1]]['height'] = $image_size[1];
}
sort($images);
var_dump($images);

score -1 · Answer 3 · answered May 03 '14 at 21:05

-1

uasort should work fine:

uasort( $height, function ( $a, $b ) { if ( $a == 0 ) { return 0; } else { return ( $a > $b ) ? -1 : 1; } } );

If I do this:

$arr = array();
$arr[0] = 512;
$arr[1] = 1024;
uasort( $arr, function ( $a, $b ) { if ( $a == 0 ) { return 0; } else { return ( $a > $b ) ? -1 : 1; } } );
var_dump( $arr );
var_dump( $arr[0] );
var_dump( $arr[1] );

I get:

array(2) {
  [1]=>
  int(1024)
  [0]=>
  int(512)
}
int(512)
int(1024)

answered May 03 '14 at 21:05

Krenair

570
5
21

-1. Now connection `width-height` is lost. – Sharikov Vladislav May 03 '14 at 21:06
Um, it keeps the same keys while reordering the array. – Krenair May 03 '14 at 21:09
So provide full answer and tell about it. I don't think current answer can help. – Sharikov Vladislav May 03 '14 at 21:12
There's not much more to say. The question says they had no luck with uasort but it should be working fine. – Krenair May 03 '14 at 21:13
The question is: `PHP - Sort array of images by height`, but not `PHP - Sort array by uasort() function` now works`. But as you wish. – Sharikov Vladislav May 03 '14 at 21:15

PHP - Sort array of images by height

3 Answers3