Modify PHP code to get reverse order of sql output? - php

Question

Is it possible to modify this code to return the categories in reverse order (i.e Highest ID first?) It's currently displaying the output with the lowest ID first. Many thanks in advance!
$imageCols = JRequest::getVar("imageCols");
$thumbWidth = JRequest::getVar("categoryThumbWidth", 4);
$columnWidth = floor(100 / $imageCols);
$document =JFactory::getDocument();
$document->addStyleSheet('components/com_groovygallery/css/groovygallery.css');
$document->addScript( JURI::base().'components/com_groovygallery/js/modernizr.custom.84782.js' );
$document->addScript( JURI::base().'components/com_groovygallery/js/masonry.pkgd.min.js' );
<?php if($this->params->get('show_page_heading')){?><h2><?php echo $this->params->get('page_heading');?></h2><?php } ?>
<div id="groovyGalleryCats" data-masonry-options='{ "columnWidth": 200, "itemSelector": ".groovyGalleryCat" }'>
<?php
foreach($this->categories as $key=>$category){
$params = json_decode($category->params);
$catImage = JURI::base().$params->image;
?>
<a class="groovyGalleryCat" href="<?php echo JRoute::_('index.php?option=com_groovygallery&view=images&filter_category='.$category->id); ?>" >
<?php if($params->image){ ?><img src="<?php echo JURI::base().'components/com_groovygallery/timthumb.php?src='. $catImage . '&zc=2&w='.$thumbWidth;?>" alt="<?php echo $category->title;?>" /> <?php } ?>
<?php echo $category->title;?>
<?php //echo $category->description;?>
</a>
<?php
}
?>
</div>
<style>
a.groovyGalleryCat {width:<?php echo $columnWidth;?>%;}
</style>
<script src="<?php echo JURI::base().'components/com_groovygallery/js/init-cat.js'; ?>" defer="defer"></script>

Answer 1

You can reorder the array like this (supposing that the id property is public...):
uasort($this->categories, function($a, $b) {
return $a->id > $b->id ? -1 : 1;
});