在joomla k2 php中列出没有重复的类别

I want to make a filter based on category name for a list of items in joomla k2. I'm able to get category name from all the items, but there are items from the same category, so i get duplicated category name. Here my code

 <div class="btn-toolbar filters">
<?php
    $numofitems = count($items);
    if($numofitems)
    {
        foreach ($items as $key=>$item)
        {
        ?>
        <div data-toggle="buttons" class="btn-group">
          <label class="btn btn-default">
            <input type="checkbox" value="<?php echo $item->categoryalias; ?>" >
            <?php echo $item->categoryname; ?>
          </label>

        </div>
        <?php } ?>

    <div class="clr"></div>

<?php } ?>
</div>

I think i need an array and then get unique values from this array, but i really suck with php. Here demo link Demo

You could always try using PHP's array_unique function which simple removes duplicates from an array.

So replace your current foreach loop with the following.

foreach (array_unique($items) as $key=>$item) {
    // rest of code here
}