isChildCategory example

$depth = $request->query->getInt('depth', $request->request->getInt('depth', 2));

        $metaInfo = $this->getCategoryMetaInfo($activeId, $rootId);

        $active = $this->getMetaInfoById($activeId, $metaInfo);

        $root = $this->getMetaInfoById($rootId, $metaInfo);

        // Validate the provided category is part of the sales channel         $this->validate($activeId, $active['path'], $context);

        $isChild = $this->isChildCategory($activeId, $active['path'], $rootId);

        // If the provided activeId is not part of the rootId, a fallback to the rootId must be made here.         // The passed activeId is therefore part of another navigation and must therefore not be loaded.         // The availability validation has already been done in the `validate` function.         if (!$isChild) {
            $activeId = $rootId;
        }

        $categories = new CategoryCollection();
        if ($depth > 0) {
            // Load the first two levels without using the activeId in the query