如何使用PHP将项目数组重新排列为3列？

Question

I have an array of menu items that I'm printing out to the screen using a foreach loop into a single, continuous, unordered list. Because of CSS/design, they display on the screen in 3 columns in this order...

1 2 3
4 5 6
7 8 9

But I need them to display like this...

1 4 7
2 5 8
3 6 9

Is there a way I can, without changing the HTML structure and still within a single for/foreach loop, print out the same items so that they are arranged in the latter configuration?

Example code

<ul>
     <?php  
         foreach($nav_menu as $nav):
             echo "<li><a href='" . $nav->url . "'>" . $nav->title . "</a></li>";
         endforeach;
     ?>
</ul>

Answer 1

You can try this:

<ul>
     <?php  
         foreach($nav_menu as $index => $nav):
             $array_index = ($index / 3) + 3 * ($index % 3);
             echo "<li><a href='" . $nav_menu[$array_index]->url . "'>" . $nav_menu[$array_index]->title . "</a></li>";
         endforeach;
     ?>
</ul>