clean up

src-php/app/internship/model/ArticleDao.php

@@ -11,15 +11,16 @@ class ArticleDao {
 		$this->em = $em;
 	}
 
-	function getArticles() {
-		$this->em->createSimpleCriteria(Article::class)->toQuery()->fetchArray();
+	function getArticles(): array {
+		return $this->em->createSimpleCriteria(Article::class)->toQuery()->fetchArray();
 	}
 
-	function getArticlesByCategoryName(string $categoryName) {
-		$this->em->createSimpleCriteria(Article::class, array('categoryName' => $categoryName))->toQuery()->fetchArray();
+	function getArticlesByCategoryName(string $categoryName): array {
+		return $this->em->createSimpleCriteria(Article::class, array('categoryName' => $categoryName))->toQuery()
+				->fetchArray();
 	}
 
-	function getArticleById(int $id) {
-		return $this->em->createSimpleCriteria(Article::class, array('id' => $id));
+	function getArticleById(int $id): ?Article {
+		return $this->em->find(Article::class, $id);
 	}
 }