diff --git a/apps/basic/tests/acceptance/WebGuy.php b/apps/basic/tests/acceptance/WebGuy.php
index 397761c18f0..e6cc370741f 100644
--- a/apps/basic/tests/acceptance/WebGuy.php
+++ b/apps/basic/tests/acceptance/WebGuy.php
@@ -36,7 +36,7 @@ class WebGuy extends \Codeception\AbstractGuy
      *
      * ``` php
      * <?php
-     * $I->submitForm('#login', array('login' => 'davert', 'password' => '123456'));
+     * $I->submitForm('#login', ['login' => 'davert', 'password' => '123456']);
      *
      * ```
      *
@@ -55,7 +55,7 @@ class WebGuy extends \Codeception\AbstractGuy
      *
      * ``` php
      * <?php
-     * $I->submitForm('#userForm', array('user' => array('login' => 'Davert', 'password' => '123456', 'agree' => true)));
+     * $I->submitForm('#userForm', ['user' => ['login' => 'Davert', 'password' => '123456', 'agree' => true]]);
      *
      * ```
      * Note, that pricing plan will be set to Paid, as it's selected on page.
@@ -89,8 +89,8 @@ public function submitForm($selector, $params) {
      *
      * ``` php
      * <?php
-     * $I->sendAjaxPostRequest('/updateSettings', array('notifications' => true); // POST
-     * $I->sendAjaxGetRequest('/updateSettings', array('notifications' => true); // GET
+     * $I->sendAjaxPostRequest('/updateSettings', ['notifications' => true]; // POST
+     * $I->sendAjaxGetRequest('/updateSettings', ['notifications' => true]; // GET
      *
      * ```
      *
@@ -202,12 +202,12 @@ public function amHttpAuthenticated($username, $password) {
      * // from the official Guzzle manual
      * $I->amGoingTo('Sign all requests with OAuth');
      * $I->executeInGuzzle(function (\Guzzle\Http\Client $client) {
-     *      $client->addSubscriber(new Guzzle\Plugin\Oauth\OauthPlugin(array(
+     *      $client->addSubscriber(new Guzzle\Plugin\Oauth\OauthPlugin([
      *                  'consumer_key'    => '***',
      *                  'consumer_secret' => '***',
      *                  'token'           => '***',
      *                  'token_secret'    => '***'
-     *      )));
+     *      ]));
      * });
      * ?>
      * ```
diff --git a/apps/basic/tests/functional/TestGuy.php b/apps/basic/tests/functional/TestGuy.php
index 767d5640ad5..58baf563ea8 100644
--- a/apps/basic/tests/functional/TestGuy.php
+++ b/apps/basic/tests/functional/TestGuy.php
@@ -832,7 +832,7 @@ public function dontSeeInField($field, $value) {
      *
      * ``` php
      * <?php
-     * $I->submitForm('#login', array('login' => 'davert', 'password' => '123456'));
+     * $I->submitForm('#login', ['login' => 'davert', 'password' => '123456']);
      *
      * ```
      *
@@ -851,7 +851,7 @@ public function dontSeeInField($field, $value) {
      *
      * ``` php
      * <?php
-     * $I->submitForm('#userForm', array('user' => array('login' => 'Davert', 'password' => '123456', 'agree' => true)));
+     * $I->submitForm('#userForm', ['user' => ['login' => 'Davert', 'password' => '123456', 'agree' => true]]);
      *
      * ```
      * Note, that pricing plan will be set to Paid, as it's selected on page.
@@ -1042,8 +1042,8 @@ public function sendAjaxGetRequest($uri, $params = null) {
      *
      * ``` php
      * <?php
-     * $I->sendAjaxPostRequest('/updateSettings', array('notifications' => true); // POST
-     * $I->sendAjaxGetRequest('/updateSettings', array('notifications' => true); // GET
+     * $I->sendAjaxPostRequest('/updateSettings', ['notifications' => true]; // POST
+     * $I->sendAjaxGetRequest('/updateSettings', ['notifications' => true]; // GET
      *
      * ```
      *
diff --git a/extensions/composer/yii/composer/InstallerPlugin.php b/extensions/composer/yii/composer/InstallerPlugin.php
index 519363dd4f5..0b8ce5fffda 100644
--- a/extensions/composer/yii/composer/InstallerPlugin.php
+++ b/extensions/composer/yii/composer/InstallerPlugin.php
@@ -28,7 +28,7 @@ public function activate(Composer $composer, IOInterface $io)
 		$composer->getInstallationManager()->addInstaller($installer);
 		$file = rtrim($composer->getConfig()->get('vendor-dir'), '/') . '/yii-extensions.php';
 		if (!is_file($file)) {
-			file_put_contents($file, "<?php\nreturn array();\n");
+			file_put_contents($file, "<?php\nreturn [];\n");
 		}
 	}
 }
diff --git a/framework/yii/base/Application.php b/framework/yii/base/Application.php
index 07e84284627..27dc37d7949 100644
--- a/framework/yii/base/Application.php
+++ b/framework/yii/base/Application.php
@@ -128,7 +128,7 @@ abstract class Application extends Module
 	 * ]
 	 * ~~~
 	 */
-	public $extensions = array();
+	public $extensions = [];
 
 	/**
 	 * @var string Used to reserve memory for fatal error handler.