PHP：计算数组中的项目，将总数除以2，创建两个UL列表，其中包含来自数组的项目的相同数量的元素

Question

I have an array containing data (ID numbers and data associated with them).

The number of items in the array is always variable and not known.

I want to split this array in two equal parts IF there's more than 2 items in the original array (not the slice).

Then I want to create two indipendent UL lists containing the resulting array slices items. If the total number of items in the original array is odd, the first list should carry one more item.

I came up with this, but I'm sure I'm doing it wrong... the content shown in the output is almost the same for each UL list, just reordered, plus in my case the number is odd (if I echo $items it comes up with 3.5).

  $panels = get_field('related_content');
  $items = count($panels);
  if ($items > 2) {
      $split = $items / 2;
      $firsthalf = array_slice($panels, $plit );
      $secondhalf = array_slice($panels, 0, $plit);
      echo '<div class="related-carousel"><ul>'; 
      foreach($firsthalf as $post_object) :
              printf('<li><a target="_blank" title="'.get_the_title($post_object->ID).'" href="'.get_permalink($post_object->ID).'"><span class="thumb">'.get_the_post_thumbnail($post_object->ID, 'smallest').'</span><span class="thumb-title"><h6>'.get_the_title($post_object->ID).'</h6></span></a><span>'.sg_get_the_excerpt().'</span></li>');
      endforeach;
      echo'</ul></div>';
      echo '<div class="related-carousel"><ul>'; 
     foreach($secondhalf as $post_object) :
             printf('<li><a target="_blank" title="'.get_the_title($post_object->ID).'" href="'.get_permalink($post_object->ID).'"><span class="thumb">'.get_the_post_thumbnail($post_object->ID, 'smallest').'</span><span class="thumb-title"><h6>'.get_the_title($post_object->ID).'</h6></span></a><span>'.sg_get_the_excerpt().'</span></li>');
     endforeach;
     echo'</ul></div>';
  }
  else {
        echo '<div class="related-carousel"><ul>';  
        foreach($panels as $post_object) :
                printf('<li><a target="_blank" title="'.get_the_title($post_object->ID).'" href="'.get_permalink($post_object->ID).'"><span class="thumb">'.get_the_post_thumbnail($post_object->ID, 'smallest').'</span><span class="thumb-title"><h6>'.get_the_title($post_object->ID).'</h6></span></a><span>'.sg_get_the_excerpt().'</span></li>');
        endforeach;
        echo'</ul></div>';
  }

Answer 1

You need to change the argument $plit of array_slice into $split! It's always useful to turn on error reporting which helps with such errors: error_reporting(E_ALL).

Could be you need to change your $split variable, e.g. by using ceil(), edit: look at AndVla answer