php if in_array controller blog index category search categories this-

<?php
		if(in_array($controller, ['blog', 'index', 'category', 'search'])){
            $categories = $this->cached->get('categories.cache');
            if ($categories === null) {
                $categories = Categories::find();
                $this->cached->save('categories.cache', $categories);
            }
            $this->view->setVar(
                'categories', $categories
            );
        }