Display pictures from a folder in the specific way – PHP

I am trying to create a dynamic gallery in php with specific order of pictures on the page, but I can’t find the function or piece of php code to do so.

Conditions:

1. The gallery must be dynamic, pictures will be coming from a folder via php, because when I’ll add/upload more pictures in the folder they must be displayed on the page without adding manually the html tags in. ( this part is easy, problem is the condition 2 ).
2. The first row will have 5 pictures, the second – 4 pictures (important for the specific effect).

My code:

    $files = glob("layout/gallery/*.jpg");

      rsort($files, SORT_NATURAL);

      for ($i=0; $i < count($files); $i++) {

        for( ; $i<5; $i++){
        $one = $files[$i];
        echo '<img src="'.$one.'">' . '<br><br>';
        }

echo '<br>';

        for( ; $i<9; $i++){
        $two = $files[$i];
        echo '<img src="'.$two.'">' . '<br><br>';
        }

      }

The code works well, but it just displays 9 pictures obviously. I was unable to make it dynamic displaying 5 pictures first, 4 pictures after and stay this way in a loop till displays all pictures from that folder.

Answer

You can take advantage of the array_splice function that removes elements from the array everytime it returns those elements :

$files = glob("layout/gallery/*.jpg");

rsort($files, SORT_NATURAL);

// split the files in rows
$rows = [];
while(count($files) != 0) {
    // even rows have 5 elements, odd ones have 4
    $num_files_to_splice = count($rows) % 2 == 0 ? 5 : 4;
    $rows[] = array_splice($files, 0, $num_files_to_splice);
}

// display them accordingly
foreach($rows as $row) {
    foreach($row as $file) {
        echo '<img src="'.$file.'">';
    }
    echo '<br><br>';
}