diff --git a/src/ExpressionParser.php b/src/ExpressionParser.php
index 243c7f672..5da4db51b 100644
--- a/src/ExpressionParser.php
+++ b/src/ExpressionParser.php
@@ -255,7 +255,9 @@ class ExpressionParser
                     $this->parser->getStream()->next();
                     $node = new NameExpression($token->getValue(), $token->getLine());
                     break;
-                } elseif (isset($this->unaryOperators[$token->getValue()])) {
+                }
+
+                if (isset($this->unaryOperators[$token->getValue()])) {
                     $class = $this->unaryOperators[$token->getValue()]['class'];
                     if (!\in_array($class, [NegUnary::class, PosUnary::class])) {
                         throw new SyntaxError(sprintf('Unexpected unary operator "%s".', $token->getValue()), $token->getLine(), $this->parser->getStream()->getSourceContext());
diff --git a/src/Extension/CoreExtension.php b/src/Extension/CoreExtension.php
index 7e9fd7659..5ad41c247 100644
--- a/src/Extension/CoreExtension.php
+++ b/src/Extension/CoreExtension.php
@@ -649,7 +649,7 @@ function twig_slice(Environment $env, $item, $start, $length = null, $preserveKe
 
     $item = (string) $item;
 
-    return (string) mb_substr($item, $start, $length, $env->getCharset());
+    return mb_substr($item, $start, $length, $env->getCharset());
 }
 
 /**
@@ -802,8 +802,8 @@ function twig_get_array_keys_filter($array)
             $array = $array->getIterator();
         }
 
+        $keys = [];
         if ($array instanceof \Iterator) {
-            $keys = [];
             $array->rewind();
             while ($array->valid()) {
                 $keys[] = $array->key();
@@ -813,7 +813,6 @@ function twig_get_array_keys_filter($array)
             return $keys;
         }
 
-        $keys = [];
         foreach ($array as $key => $item) {
             $keys[] = $key;
         }
diff --git a/src/Loader/ArrayLoader.php b/src/Loader/ArrayLoader.php
index a6164bb1a..5d726c35a 100644
--- a/src/Loader/ArrayLoader.php
+++ b/src/Loader/ArrayLoader.php
@@ -45,7 +45,6 @@ final class ArrayLoader implements LoaderInterface
 
     public function getSourceContext(string $name): Source
     {
-        $name = (string) $name;
         if (!isset($this->templates[$name])) {
             throw new LoaderError(sprintf('Template "%s" is not defined.', $name));
         }
diff --git a/src/Loader/FilesystemLoader.php b/src/Loader/FilesystemLoader.php
index 0db9e937c..a15033168 100644
--- a/src/Loader/FilesystemLoader.php
+++ b/src/Loader/FilesystemLoader.php
@@ -51,7 +51,7 @@ class FilesystemLoader implements LoaderInterface
      */
     public function getPaths(string $namespace = self::MAIN_NAMESPACE): array
     {
-        return isset($this->paths[$namespace]) ? $this->paths[$namespace] : [];
+        return $this->paths[$namespace] ?? [];
     }
 
     /**
diff --git a/src/Node/IncludeNode.php b/src/Node/IncludeNode.php
index d01f1fca3..d540d6b23 100644
--- a/src/Node/IncludeNode.php
+++ b/src/Node/IncludeNode.php
@@ -29,7 +29,7 @@ class IncludeNode extends Node implements NodeOutputInterface
             $nodes['variables'] = $variables;
         }
 
-        parent::__construct($nodes, ['only' => (bool) $only, 'ignore_missing' => (bool) $ignoreMissing], $lineno, $tag);
+        parent::__construct($nodes, ['only' => $only, 'ignore_missing' => $ignoreMissing], $lineno, $tag);
     }
 
     public function compile(Compiler $compiler): void
diff --git a/src/NodeVisitor/EscaperNodeVisitor.php b/src/NodeVisitor/EscaperNodeVisitor.php
index fafceb4db..fe56ea307 100644
--- a/src/NodeVisitor/EscaperNodeVisitor.php
+++ b/src/NodeVisitor/EscaperNodeVisitor.php
@@ -196,7 +196,7 @@ final class EscaperNodeVisitor implements NodeVisitorInterface
     {
         $line = $node->getTemplateLine();
         $name = new ConstantExpression('escape', $line);
-        $args = new Node([new ConstantExpression((string) $type, $line), new ConstantExpression(null, $line), new ConstantExpression(true, $line)]);
+        $args = new Node([new ConstantExpression($type, $line), new ConstantExpression(null, $line), new ConstantExpression(true, $line)]);
 
         return new FilterExpression($node, $name, $args, $line);
     }
diff --git a/src/Parser.php b/src/Parser.php
index b8aac05f2..6103695e0 100644
--- a/src/Parser.php
+++ b/src/Parser.php
@@ -193,7 +193,7 @@ class Parser
 
     public function peekBlockStack()
     {
-        return isset($this->blockStack[\count($this->blockStack) - 1]) ? $this->blockStack[\count($this->blockStack) - 1] : null;
+        return $this->blockStack[\count($this->blockStack) - 1] ?? null;
     }
 
     public function popBlockStack(): void
diff --git a/src/Profiler/Dumper/BlackfireDumper.php b/src/Profiler/Dumper/BlackfireDumper.php
index 3fab5db1f..03abe0fa0 100644
--- a/src/Profiler/Dumper/BlackfireDumper.php
+++ b/src/Profiler/Dumper/BlackfireDumper.php
@@ -28,13 +28,13 @@ final class BlackfireDumper
         $str = <<<EOF
 file-format: BlackfireProbe
 cost-dimensions: wt mu pmu
-request-start: {$start}
+request-start: $start
 
 
 EOF;
 
         foreach ($data as $name => $values) {
-            $str .= "{$name}//{$values['ct']} {$values['wt']} {$values['mu']} {$values['pmu']}\n";
+            $str .= "$name//{$values['ct']} {$values['wt']} {$values['mu']} {$values['pmu']}\n";
         }
 
         return $str;
diff --git a/src/Test/NodeTestCase.php b/src/Test/NodeTestCase.php
index 646402417..3b8b2c86c 100644
--- a/src/Test/NodeTestCase.php
+++ b/src/Test/NodeTestCase.php
@@ -53,7 +53,7 @@ abstract class NodeTestCase extends TestCase
 
     protected function getVariableGetter($name, $line = false)
     {
-        $line = $line > 0 ? "// line {$line}\n" : '';
+        $line = $line > 0 ? "// line $line\n" : '';
 
         return sprintf('%s($context["%s"] ?? null)', $line, $name);
     }
diff --git a/src/TokenParser/ForTokenParser.php b/src/TokenParser/ForTokenParser.php
index b6d3b4e41..bac8ba2da 100644
--- a/src/TokenParser/ForTokenParser.php
+++ b/src/TokenParser/ForTokenParser.php
@@ -52,12 +52,11 @@ final class ForTokenParser extends AbstractTokenParser
             $keyTarget = $targets->getNode(0);
             $keyTarget = new AssignNameExpression($keyTarget->getAttribute('name'), $keyTarget->getTemplateLine());
             $valueTarget = $targets->getNode(1);
-            $valueTarget = new AssignNameExpression($valueTarget->getAttribute('name'), $valueTarget->getTemplateLine());
         } else {
             $keyTarget = new AssignNameExpression('_key', $lineno);
             $valueTarget = $targets->getNode(0);
-            $valueTarget = new AssignNameExpression($valueTarget->getAttribute('name'), $valueTarget->getTemplateLine());
         }
+        $valueTarget = new AssignNameExpression($valueTarget->getAttribute('name'), $valueTarget->getTemplateLine());
 
         return new ForNode($keyTarget, $valueTarget, $seq, null, $body, $else, $lineno, $this->getTag());
     }