diff --git a/src/Symfony/Component/CssSelector/Exception/ExpressionErrorException.php b/src/Symfony/Component/CssSelector/Exception/ExpressionErrorException.php
index 756a12a75a..fd5deeabe4 100644
--- a/src/Symfony/Component/CssSelector/Exception/ExpressionErrorException.php
+++ b/src/Symfony/Component/CssSelector/Exception/ExpressionErrorException.php
@@ -19,6 +19,6 @@ namespace Symfony\Component\CssSelector\Exception;
  *
  * @author Jean-François Simon <jeanfrancois.simon@sensiolabs.com>
  */
-class ExpressionErrorException extends ParseException implements ExceptionInterface
+class ExpressionErrorException extends ParseException
 {
 }
diff --git a/src/Symfony/Component/CssSelector/Exception/InternalErrorException.php b/src/Symfony/Component/CssSelector/Exception/InternalErrorException.php
index 2decde67fe..e60e5ed0f2 100644
--- a/src/Symfony/Component/CssSelector/Exception/InternalErrorException.php
+++ b/src/Symfony/Component/CssSelector/Exception/InternalErrorException.php
@@ -19,6 +19,6 @@ namespace Symfony\Component\CssSelector\Exception;
  *
  * @author Jean-François Simon <jeanfrancois.simon@sensiolabs.com>
  */
-class InternalErrorException extends ParseException implements ExceptionInterface
+class InternalErrorException extends ParseException
 {
 }
diff --git a/src/Symfony/Component/CssSelector/Exception/SyntaxErrorException.php b/src/Symfony/Component/CssSelector/Exception/SyntaxErrorException.php
index 831b001340..418bc301cb 100644
--- a/src/Symfony/Component/CssSelector/Exception/SyntaxErrorException.php
+++ b/src/Symfony/Component/CssSelector/Exception/SyntaxErrorException.php
@@ -21,7 +21,7 @@ use Symfony\Component\CssSelector\Parser\Token;
  *
  * @author Jean-François Simon <jeanfrancois.simon@sensiolabs.com>
  */
-class SyntaxErrorException extends ParseException implements ExceptionInterface
+class SyntaxErrorException extends ParseException
 {
     /**
      * @param string $expectedValue
diff --git a/src/Symfony/Component/DependencyInjection/Dumper/GraphvizDumper.php b/src/Symfony/Component/DependencyInjection/Dumper/GraphvizDumper.php
index e7deac29aa..fdd71b36ee 100644
--- a/src/Symfony/Component/DependencyInjection/Dumper/GraphvizDumper.php
+++ b/src/Symfony/Component/DependencyInjection/Dumper/GraphvizDumper.php
@@ -173,7 +173,7 @@ class GraphvizDumper extends Dumper
         foreach ($container->getServiceIds() as $id) {
             $service = $container->get($id);
 
-            if (in_array($id, array_keys($container->getAliases()))) {
+            if (array_key_exists($id, $container->getAliases())) {
                 continue;
             }
 
diff --git a/src/Symfony/Component/Filesystem/Filesystem.php b/src/Symfony/Component/Filesystem/Filesystem.php
index 135ffc959c..b7ae31bb71 100644
--- a/src/Symfony/Component/Filesystem/Filesystem.php
+++ b/src/Symfony/Component/Filesystem/Filesystem.php
@@ -41,10 +41,9 @@ class Filesystem
 
         $this->mkdir(dirname($targetFile));
 
-        if (!$override && is_file($targetFile) && null === parse_url($originFile, PHP_URL_HOST)) {
+        $doCopy = true;
+        if (!$override && null === parse_url($originFile, PHP_URL_HOST) && is_file($targetFile)) {
             $doCopy = filemtime($originFile) > filemtime($targetFile);
-        } else {
-            $doCopy = true;
         }
 
         if ($doCopy) {
@@ -274,7 +273,7 @@ class Filesystem
      */
     public function symlink($originDir, $targetDir, $copyOnWindows = false)
     {
-        if (!function_exists('symlink') && $copyOnWindows) {
+        if ($copyOnWindows && !function_exists('symlink')) {
             $this->mirror($originDir, $targetDir);
 
             return;
@@ -291,16 +290,14 @@ class Filesystem
             }
         }
 
-        if (!$ok) {
-            if (true !== @symlink($originDir, $targetDir)) {
-                $report = error_get_last();
-                if (is_array($report)) {
-                    if ('\\' === DIRECTORY_SEPARATOR && false !== strpos($report['message'], 'error code(1314)')) {
-                        throw new IOException('Unable to create symlink due to error code 1314: \'A required privilege is not held by the client\'. Do you have the required Administrator-rights?');
-                    }
+        if (!$ok && true !== @symlink($originDir, $targetDir)) {
+            $report = error_get_last();
+            if (is_array($report)) {
+                if ('\\' === DIRECTORY_SEPARATOR && false !== strpos($report['message'], 'error code(1314)')) {
+                    throw new IOException('Unable to create symlink due to error code 1314: \'A required privilege is not held by the client\'. Do you have the required Administrator-rights?');
                 }
-                throw new IOException(sprintf('Failed to create symbolic link from %s to %s', $originDir, $targetDir));
             }
+            throw new IOException(sprintf('Failed to create symbolic link from %s to %s', $originDir, $targetDir));
         }
     }
 
@@ -339,9 +336,9 @@ class Filesystem
         $endPathRemainder = implode('/', array_slice($endPathArr, $index));
 
         // Construct $endPath from traversing to the common path, then to the remaining $endPath
-        $relativePath = $traverser.(strlen($endPathRemainder) > 0 ? $endPathRemainder.'/' : '');
+        $relativePath = $traverser.('' !== $endPathRemainder ? $endPathRemainder.'/' : '');
 
-        return (strlen($relativePath) === 0) ? './' : $relativePath;
+        return '' === $relativePath ? './' : $relativePath;
     }
 
     /**
diff --git a/src/Symfony/Component/Form/NativeRequestHandler.php b/src/Symfony/Component/Form/NativeRequestHandler.php
index a888967bb3..7c883f12eb 100644
--- a/src/Symfony/Component/Form/NativeRequestHandler.php
+++ b/src/Symfony/Component/Form/NativeRequestHandler.php
@@ -184,10 +184,10 @@ class NativeRequestHandler implements RequestHandlerInterface
             unset($files[$k]);
         }
 
-        foreach (array_keys($data['name']) as $key) {
+        foreach ($data['name'] as $key => $name) {
             $files[$key] = self::fixPhpFilesArray(array(
                 'error' => $data['error'][$key],
-                'name' => $data['name'][$key],
+                'name' => $name,
                 'type' => $data['type'][$key],
                 'tmp_name' => $data['tmp_name'][$key],
                 'size' => $data['size'][$key],
diff --git a/src/Symfony/Component/HttpFoundation/FileBag.php b/src/Symfony/Component/HttpFoundation/FileBag.php
index 467c31576b..43b8af3c83 100644
--- a/src/Symfony/Component/HttpFoundation/FileBag.php
+++ b/src/Symfony/Component/HttpFoundation/FileBag.php
@@ -140,10 +140,10 @@ class FileBag extends ParameterBag
             unset($files[$k]);
         }
 
-        foreach (array_keys($data['name']) as $key) {
+        foreach ($data['name'] as $key => $name) {
             $files[$key] = $this->fixPhpFilesArray(array(
                 'error' => $data['error'][$key],
-                'name' => $data['name'][$key],
+                'name' => $name,
                 'type' => $data['type'][$key],
                 'tmp_name' => $data['tmp_name'][$key],
                 'size' => $data['size'][$key],
diff --git a/src/Symfony/Component/HttpFoundation/Request.php b/src/Symfony/Component/HttpFoundation/Request.php
index f6c319c9ed..de798de27a 100644
--- a/src/Symfony/Component/HttpFoundation/Request.php
+++ b/src/Symfony/Component/HttpFoundation/Request.php
@@ -1549,7 +1549,7 @@ class Request
         foreach (array_keys($languages) as $lang) {
             if (strstr($lang, '-')) {
                 $codes = explode('-', $lang);
-                if ($codes[0] == 'i') {
+                if ('i' === $codes[0]) {
                     // Language not listed in ISO 639 that are not variants
                     // of any listed language, which can be registered with the
                     // i-prefix, such as i-cherokee
@@ -1558,7 +1558,7 @@ class Request
                     }
                 } else {
                     for ($i = 0, $max = count($codes); $i < $max; $i++) {
-                        if ($i == 0) {
+                        if ($i === 0) {
                             $lang = strtolower($codes[0]);
                         } else {
                             $lang .= '_'.strtoupper($codes[$i]);
diff --git a/src/Symfony/Component/HttpFoundation/Tests/File/MimeType/MimeTypeTest.php b/src/Symfony/Component/HttpFoundation/Tests/File/MimeType/MimeTypeTest.php
index 81c581291c..b2a573e27a 100644
--- a/src/Symfony/Component/HttpFoundation/Tests/File/MimeType/MimeTypeTest.php
+++ b/src/Symfony/Component/HttpFoundation/Tests/File/MimeType/MimeTypeTest.php
@@ -75,7 +75,7 @@ class MimeTypeTest extends \PHPUnit_Framework_TestCase
             $this->markTestSkipped('Can not verify chmod operations on Windows');
         }
 
-        if (in_array(get_current_user(), array('root'))) {
+        if ('root' === get_current_user()) {
             $this->markTestSkipped('This test will fail if run under superuser');
         }
 
diff --git a/src/Symfony/Component/Translation/Loader/CsvFileLoader.php b/src/Symfony/Component/Translation/Loader/CsvFileLoader.php
index a5f590dba4..ddcf595baf 100644
--- a/src/Symfony/Component/Translation/Loader/CsvFileLoader.php
+++ b/src/Symfony/Component/Translation/Loader/CsvFileLoader.php
@@ -22,7 +22,7 @@ use Symfony\Component\Config\Resource\FileResource;
  *
  * @api
  */
-class CsvFileLoader extends ArrayLoader implements LoaderInterface
+class CsvFileLoader extends ArrayLoader
 {
     private $delimiter = ';';
     private $enclosure = '"';
diff --git a/src/Symfony/Component/Translation/Loader/IniFileLoader.php b/src/Symfony/Component/Translation/Loader/IniFileLoader.php
index 616fa7e0e7..3f01ab4e99 100644
--- a/src/Symfony/Component/Translation/Loader/IniFileLoader.php
+++ b/src/Symfony/Component/Translation/Loader/IniFileLoader.php
@@ -20,7 +20,7 @@ use Symfony\Component\Config\Resource\FileResource;
  *
  * @author stealth35
  */
-class IniFileLoader extends ArrayLoader implements LoaderInterface
+class IniFileLoader extends ArrayLoader
 {
     /**
      * {@inheritdoc}
diff --git a/src/Symfony/Component/Translation/Loader/MoFileLoader.php b/src/Symfony/Component/Translation/Loader/MoFileLoader.php
index 3f0dd921ee..18d07b0ccc 100644
--- a/src/Symfony/Component/Translation/Loader/MoFileLoader.php
+++ b/src/Symfony/Component/Translation/Loader/MoFileLoader.php
@@ -18,7 +18,7 @@ use Symfony\Component\Config\Resource\FileResource;
 /**
  * @copyright Copyright (c) 2010, Union of RAD http://union-of-rad.org (http://lithify.me/)
  */
-class MoFileLoader extends ArrayLoader implements LoaderInterface
+class MoFileLoader extends ArrayLoader
 {
     /**
      * Magic used for validating the format of a MO file as well as
diff --git a/src/Symfony/Component/Translation/Loader/PhpFileLoader.php b/src/Symfony/Component/Translation/Loader/PhpFileLoader.php
index 55913d6c75..1cc9d06d9c 100644
--- a/src/Symfony/Component/Translation/Loader/PhpFileLoader.php
+++ b/src/Symfony/Component/Translation/Loader/PhpFileLoader.php
@@ -22,7 +22,7 @@ use Symfony\Component\Config\Resource\FileResource;
  *
  * @api
  */
-class PhpFileLoader extends ArrayLoader implements LoaderInterface
+class PhpFileLoader extends ArrayLoader
 {
     /**
      * {@inheritdoc}
diff --git a/src/Symfony/Component/Translation/Loader/PoFileLoader.php b/src/Symfony/Component/Translation/Loader/PoFileLoader.php
index 6d5e835568..9f51af3ba6 100644
--- a/src/Symfony/Component/Translation/Loader/PoFileLoader.php
+++ b/src/Symfony/Component/Translation/Loader/PoFileLoader.php
@@ -19,7 +19,7 @@ use Symfony\Component\Config\Resource\FileResource;
  * @copyright Copyright (c) 2010, Union of RAD http://union-of-rad.org (http://lithify.me/)
  * @copyright Copyright (c) 2012, Clemens Tolboom
  */
-class PoFileLoader extends ArrayLoader implements LoaderInterface
+class PoFileLoader extends ArrayLoader
 {
     public function load($resource, $locale, $domain = 'messages')
     {
diff --git a/src/Symfony/Component/Translation/Loader/YamlFileLoader.php b/src/Symfony/Component/Translation/Loader/YamlFileLoader.php
index 419a82dcc6..e50e0fa385 100644
--- a/src/Symfony/Component/Translation/Loader/YamlFileLoader.php
+++ b/src/Symfony/Component/Translation/Loader/YamlFileLoader.php
@@ -24,7 +24,7 @@ use Symfony\Component\Yaml\Exception\ParseException;
  *
  * @api
  */
-class YamlFileLoader extends ArrayLoader implements LoaderInterface
+class YamlFileLoader extends ArrayLoader
 {
     private $yamlParser;