如何将属性与下一个元素的属性进行比较

Question

How to get value of the next ORM element in foreach? I need something like that:

   $users = ORM::factory('Users')
       ->order_by('category', 'ASC')
       ->find_all();
    foreach($users as $user)
    {
       if($user->category != next($user->category))
       {
          echo 'Next category user';
       }
    }

Answer 1

Comparing to the next item can be difficult at times (like these). However, comparing to the previous one is usually quite easy.

Eg like this:

$users = ORM::factory('Users')
   ->order_by('category', 'ASC')
   ->find_all();
$previousCategory = null;
foreach($users as $user)
{
   if($user->category != $previousCategory)
   {
      echo 'Next category user';
   }
   $previousCategory = $user->category;
}

Answer 2

One way is to manually seek to the next element, take the values you want, then reset back to where you were. It's pretty messy but it'll do what you want:

foreach($users as $user)
{
   $current_key = $users->key();
   $next_category = $users->seek($current_key + 1) ? $users->current()->category : NULL;
   $users->seek($current_key);

   if($next_category && $user->category != $next_category)
   {
      echo 'Next category user';
   }
}