How would I sort this this foreach loop?

Question

This pulls a list of all our category thumbnails and the name. I want to sort it alphabetically.-

<?php
$category = Mage::getSingleton('catalog/layer')->getCurrentCategory();
$categories = $category->getCollection()
    ->addAttributeToSelect(array('name', 'thumbnail'))
    ->addAttributeToFilter('is_active', 1)
    ->addIdFilter($category->getChildren())
?>

<ul class="subcatthumbnails" id="cat-thumb-box">
<?php foreach ($categories as $category): ?>
    <li>
        <a href="<?php echo $category->getUrl() ?>"><img src="<?php echo Mage::getBaseUrl('media') . 'catalog' . DS . 'category' . DS . $category->getThumbnail() ?>" alt="<?php echo $this->htmlEscape($category->getName()) ?>" />
            <span><?php echo $category->getName() ?></span></a>
    </li>
<?php endforeach; ?>
</ul>

I am trying to figure out how to sort it alphabetically.

Answer 1

Try

    <?php
$category = Mage::getSingleton('catalog/layer')->getCurrentCategory();
$categories = $category->getCollection()
    ->addAttributeToSelect(array('name', 'thumbnail'))
    ->addAttributeToFilter('is_active', 1)
    ->addIdFilter($category->getChildren())
    ->addOrderField('name')
?>

Answer 2

Add this code

->setOrder('name', 'ASC')

after

->addIdFilter($category->getChildren())