如何比较属性与下一个元素' - How to compare attribute to next element's one

How to compare attribute to next element's one

如何在foreach中获得下一个ORM元素的值?我需要这样的内容:

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

与下一项进行比较有时会很困难(就像这些)。然而，比较前一个通常是很容易的。

。这样的:

$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;
}

一种方法是手动查找下一个元素，获取所需的值，然后重置回原来的位置。它很乱，但它会做你想做的:

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';
   }
}