if ():
endif;
what is this grammar and how to find a manual? thank you
<div class="am-u-sm-9 am-u-end">
<select name="category[parent_id]"
data-am-selected="{searchBox: 1, btnSize: "sm"}">
<option value="0"></option>
<?php if (isset($list)): foreach ($list as $first): ?>
<option value="<?= $first["category_id"] ?>">
<?= $first["name"] ?></option>
<?php endforeach; endif; ?>
</select>
</div>