Breaking the nested loop

Unlike other languages such as C/C++, in PHP you can use the optional param of break like this:

break 2;

In this case if you have two loops such that:

while(...) {
   while(...) {
      // do
      // something

      break 2; // skip both
   }
}

break 2 will skip both while loops.

Doc: http://php.net/manual/en/control-structures.break.php

This makes jumping over nested loops more readable than for example using goto of other languages

Use a while loop

<?php 
$count = $i = 0;
while ($count<5 && $query->posts[$i]) {
    $j = 0;
    $post = $query->posts[$i++];
    if ($images = get_children(array(
                    'post_parent' => $post->ID,
                    'post_type' => 'attachment',
                    'post_mime_type' => 'image'))
            ){              
              while ($count < 5 && $images[$j]) { 
                $count++; 
                $image = $images[$j++];
                    ..
                }               
            }
}
?>