diff --git a/Creational/AbstractFactory/WinJsonWriter.php b/Creational/AbstractFactory/WinJsonWriter.php
index 7671521..4c553a8 100644
--- a/Creational/AbstractFactory/WinJsonWriter.php
+++ b/Creational/AbstractFactory/WinJsonWriter.php
@@ -6,8 +6,12 @@ class WinJsonWriter implements JsonWriter
 {
     public function write(array $data, bool $formatted): string
     {
+        $options = 0;
 
+        if ($formatted) {
+            $options = JSON_PRETTY_PRINT;
+        }
 
-        return json_encode($data, JSON_PRETTY_PRINT);
+        return json_encode($data, $options);
     }
 }
diff --git a/Creational/Builder/Builder.php b/Creational/Builder/Builder.php
index 6bda440..eadee30 100644
--- a/Creational/Builder/Builder.php
+++ b/Creational/Builder/Builder.php
@@ -8,13 +8,13 @@ use DesignPatterns\Creational\Builder\Parts\Vehicle;
 
 interface Builder
 {
-    public function createVehicle();
+    public function createVehicle(): void;
 
-    public function addWheel();
+    public function addWheel(): void;
 
-    public function addEngine();
+    public function addEngine(): void;
 
-    public function addDoors();
+    public function addDoors(): void;
 
     public function getVehicle(): Vehicle;
 }
diff --git a/Creational/Builder/CarBuilder.php b/Creational/Builder/CarBuilder.php
index b418004..9335a13 100644
--- a/Creational/Builder/CarBuilder.php
+++ b/Creational/Builder/CarBuilder.php
@@ -14,19 +14,19 @@ class CarBuilder implements Builder
 {
     private Car $car;
 
-    public function addDoors()
+    public function addDoors(): void
     {
         $this->car->setPart('rightDoor', new Door());
         $this->car->setPart('leftDoor', new Door());
         $this->car->setPart('trunkLid', new Door());
     }
 
-    public function addEngine()
+    public function addEngine(): void
     {
         $this->car->setPart('engine', new Engine());
     }
 
-    public function addWheel()
+    public function addWheel(): void
     {
         $this->car->setPart('wheelLF', new Wheel());
         $this->car->setPart('wheelRF', new Wheel());
@@ -34,7 +34,7 @@ class CarBuilder implements Builder
         $this->car->setPart('wheelRR', new Wheel());
     }
 
-    public function createVehicle()
+    public function createVehicle(): void
     {
         $this->car = new Car();
     }
diff --git a/Creational/Builder/TruckBuilder.php b/Creational/Builder/TruckBuilder.php
index 2be7f4e..b9d57df 100644
--- a/Creational/Builder/TruckBuilder.php
+++ b/Creational/Builder/TruckBuilder.php
@@ -14,18 +14,18 @@ class TruckBuilder implements Builder
 {
     private Truck $truck;
 
-    public function addDoors()
+    public function addDoors(): void
     {
         $this->truck->setPart('rightDoor', new Door());
         $this->truck->setPart('leftDoor', new Door());
     }
 
-    public function addEngine()
+    public function addEngine(): void
     {
         $this->truck->setPart('truckEngine', new Engine());
     }
 
-    public function addWheel()
+    public function addWheel(): void
     {
         $this->truck->setPart('wheel1', new Wheel());
         $this->truck->setPart('wheel2', new Wheel());
@@ -35,7 +35,7 @@ class TruckBuilder implements Builder
         $this->truck->setPart('wheel6', new Wheel());
     }
 
-    public function createVehicle()
+    public function createVehicle(): void
     {
         $this->truck = new Truck();
     }
diff --git a/Creational/Pool/StringReverseWorker.php b/Creational/Pool/StringReverseWorker.php
index a2de032..60065de 100644
--- a/Creational/Pool/StringReverseWorker.php
+++ b/Creational/Pool/StringReverseWorker.php
@@ -4,14 +4,8 @@ declare(strict_types=1);
 
 namespace DesignPatterns\Creational\Pool;
 
-use DateTime;
-
 class StringReverseWorker
 {
-    public function __construct()
-    {
-    }
-
     public function run(string $text): string
     {
         return strrev($text);
diff --git a/Creational/Pool/WorkerPool.php b/Creational/Pool/WorkerPool.php
index 82426a9..6b4f3d8 100644
--- a/Creational/Pool/WorkerPool.php
+++ b/Creational/Pool/WorkerPool.php
@@ -20,7 +20,7 @@ class WorkerPool implements Countable
 
     public function get(): StringReverseWorker
     {
-        if (count($this->freeWorkers) == 0) {
+        if (count($this->freeWorkers) === 0) {
             $worker = new StringReverseWorker();
         } else {
             $worker = array_pop($this->freeWorkers);
@@ -31,10 +31,9 @@ class WorkerPool implements Countable
         return $worker;
     }
 
-    public function dispose(StringReverseWorker $worker)
+    public function dispose(StringReverseWorker $worker): void
     {
         $key = spl_object_hash($worker);
-
         if (isset($this->occupiedWorkers[$key])) {
             unset($this->occupiedWorkers[$key]);
             $this->freeWorkers[$key] = $worker;
diff --git a/Creational/StaticFactory/StaticFactory.php b/Creational/StaticFactory/StaticFactory.php
index 3b8a9d9..de91a85 100644
--- a/Creational/StaticFactory/StaticFactory.php
+++ b/Creational/StaticFactory/StaticFactory.php
@@ -14,13 +14,10 @@ final class StaticFactory
 {
     public static function factory(string $type): Formatter
     {
-        if ($type == 'number') {
-            return new FormatNumber();
-        }
-        if ($type == 'string') {
-            return new FormatString();
-        }
-
-        throw new InvalidArgumentException('Unknown format given');
+        return match ($type) {
+            'number' => new FormatNumber(),
+            'string' => new FormatString(),
+            default => throw new InvalidArgumentException('Unknown format given'),
+        };
     }
 }