diff --git a/src/Bridges/FormsDI/FormsExtension.php b/src/Bridges/FormsDI/FormsExtension.php
index 5b4989f89..b06ca6775 100644
--- a/src/Bridges/FormsDI/FormsExtension.php
+++ b/src/Bridges/FormsDI/FormsExtension.php
@@ -26,7 +26,7 @@ public function __construct()
 	}
 
 
-	public function afterCompile(Nette\PhpGenerator\ClassType $class)
+	public function afterCompile(Nette\PhpGenerator\ClassType $class): void
 	{
 		$initialize = $this->initialization ?? $class->getMethod('initialize');
 
diff --git a/src/Bridges/FormsLatte/Nodes/FieldNNameNode.php b/src/Bridges/FormsLatte/Nodes/FieldNNameNode.php
index a3dbb858e..46bb7a1c6 100644
--- a/src/Bridges/FormsLatte/Nodes/FieldNNameNode.php
+++ b/src/Bridges/FormsLatte/Nodes/FieldNNameNode.php
@@ -57,7 +57,7 @@ public function print(PrintContext $context): string
 	}
 
 
-	private function init(Tag $tag)
+	private function init(Tag $tag): void
 	{
 		$el = $tag->htmlElement;
 		$usedAttributes = self::findUsedAttributes($el);
diff --git a/src/Bridges/FormsLatte/Nodes/FormNNameNode.php b/src/Bridges/FormsLatte/Nodes/FormNNameNode.php
index fe569b71d..3c1213f03 100644
--- a/src/Bridges/FormsLatte/Nodes/FormNNameNode.php
+++ b/src/Bridges/FormsLatte/Nodes/FormNNameNode.php
@@ -57,7 +57,7 @@ public function print(PrintContext $context): string
 	}
 
 
-	private function init(Tag $tag)
+	private function init(Tag $tag): void
 	{
 		$el = $tag->htmlElement;
 
diff --git a/src/Forms/Container.php b/src/Forms/Container.php
index e412c1b41..9c2946ae6 100644
--- a/src/Forms/Container.php
+++ b/src/Forms/Container.php
@@ -61,29 +61,20 @@ public function setDefaults(array|object $data, bool $erase = false): static
 	 * Fill-in with values.
 	 * @internal
 	 */
-	public function setValues(array|object $data, bool $erase = false): static
+	public function setValues(array|object $values, bool $erase = false): static
 	{
-		if ($data instanceof \Traversable) {
-			$values = iterator_to_array($data);
-
-		} elseif (is_object($data) || is_array($data) || $data === null) {
-			$values = (array) $data;
-		}
+		$values = $values instanceof \Traversable
+			? iterator_to_array($values)
+			: (array) $values;
 
 		foreach ($this->getComponents() as $name => $control) {
 			if ($control instanceof Control) {
-				if (array_key_exists($name, $values)) {
-					$control->setValue($values[$name]);
-
-				} elseif ($erase) {
-					$control->setValue(null);
+				if (array_key_exists($name, $values) || $erase) {
+					$control->setValue($values[$name] ?? null);
 				}
 			} elseif ($control instanceof self) {
-				if (isset($values[$name])) {
-					$control->setValues($values[$name], $erase);
-
-				} elseif ($erase) {
-					$control->setValues([], $erase);
+				if (isset($values[$name]) || $erase) {
+					$control->setValues($values[$name] ?? [], $erase);
 				}
 			}
 		}
@@ -186,7 +177,6 @@ public function getUnsafeValues($returnType, ?array $controls = null)
 	}
 
 
-	/** @return static */
 	public function setMappedType(string $type): static
 	{
 		$this->mappedType = $type;
@@ -287,10 +277,7 @@ public function addComponent(
 	): static
 	{
 		parent::addComponent($component, $name, $insertBefore);
-		if ($this->currentGroup !== null) {
-			$this->currentGroup->add($component);
-		}
-
+		$this->currentGroup?->add($component);
 		return $this;
 	}
 
@@ -577,10 +564,7 @@ public function addContainer(string|int $name): self
 	{
 		$control = new self;
 		$control->currentGroup = $this->currentGroup;
-		if ($this->currentGroup !== null) {
-			$this->currentGroup->add($control);
-		}
-
+		$this->currentGroup?->add($control);
 		return $this[$name] = $control;
 	}
 
diff --git a/src/Forms/Controls/BaseControl.php b/src/Forms/Controls/BaseControl.php
index bac909dff..641102755 100644
--- a/src/Forms/Controls/BaseControl.php
+++ b/src/Forms/Controls/BaseControl.php
@@ -169,7 +169,7 @@ public function isFilled(): bool
 	 */
 	public function setDefaultValue($value)
 	{
-		$form = $this->getForm(false);
+		$form = $this->getForm(throw: false);
 		if ($this->isDisabled() || !$form || !$form->isAnchored() || !$form->isSubmitted()) {
 			$this->setValue($value);
 		}
@@ -182,11 +182,12 @@ public function setDefaultValue($value)
 	 * Disables or enables control.
 	 * @return static
 	 */
-	public function setDisabled(bool $value = true)
+	public function setDisabled(bool $state = true)
 	{
-		if ($this->disabled = (bool) $value) {
+		$this->disabled = $state;
+		if ($state) {
 			$this->setValue(null);
-		} elseif (($form = $this->getForm(false)) && $form->isAnchored() && $form->isSubmitted()) {
+		} elseif (($form = $this->getForm(throw: false)) && $form->isAnchored() && $form->isSubmitted()) {
 			$this->loadHttpData();
 		}
 
@@ -206,9 +207,9 @@ public function isDisabled(): bool
 	/**
 	 * Sets whether control value is excluded from $form->getValues() result.
 	 */
-	public function setOmitted(bool $value = true): static
+	public function setOmitted(bool $state = true): static
 	{
-		$this->omitted = $value;
+		$this->omitted = $state;
 		return $this;
 	}
 
diff --git a/src/Forms/Controls/Checkbox.php b/src/Forms/Controls/Checkbox.php
index 1b4cac23f..1c8ec02dc 100644
--- a/src/Forms/Controls/Checkbox.php
+++ b/src/Forms/Controls/Checkbox.php
@@ -39,7 +39,7 @@ public function __construct(string|Stringable|null $label = null)
 	public function setValue($value)
 	{
 		if (!is_scalar($value) && $value !== null) {
-			throw new Nette\InvalidArgumentException(sprintf("Value must be scalar or null, %s given in field '%s'.", get_debug_type($value), $this->name));
+			throw new Nette\InvalidArgumentException(sprintf("Value must be scalar or null, %s given in field '%s'.", get_debug_type($value), $this->getName()));
 		}
 
 		$this->value = (bool) $value;
diff --git a/src/Forms/Controls/CheckboxList.php b/src/Forms/Controls/CheckboxList.php
index a04207a2e..8b2bcc41d 100644
--- a/src/Forms/Controls/CheckboxList.php
+++ b/src/Forms/Controls/CheckboxList.php
@@ -56,8 +56,6 @@ public function getControl(): Html
 	{
 		$input = parent::getControl();
 		$items = $this->getItems();
-		reset($items);
-
 		return $this->container->setHtml(
 			Nette\Forms\Helpers::createInputList(
 				$this->translate($items),
@@ -66,7 +64,7 @@ public function getControl(): Html
 					'checked?' => $this->value,
 					'disabled:' => $this->disabled,
 					'required' => null,
-					'data-nette-rules:' => [key($items) => $input->attrs['data-nette-rules']],
+					'data-nette-rules:' => [array_key_first($items) => $input->attrs['data-nette-rules']],
 				]),
 				$this->itemLabel->attrs,
 				$this->separator,
@@ -98,7 +96,7 @@ public function getLabelPart($key = null): Html
 	{
 		$itemLabel = clone $this->itemLabel;
 		return func_num_args()
-			? $itemLabel->setText($this->translate($this->items[$key]))->for($this->getHtmlId() . '-' . $key)
+			? $itemLabel->setText($this->translate($this->getItems()[$key]))->for($this->getHtmlId() . '-' . $key)
 			: $this->getLabel();
 	}
 
diff --git a/src/Forms/Controls/ChoiceControl.php b/src/Forms/Controls/ChoiceControl.php
index 3d36d4de1..382290318 100644
--- a/src/Forms/Controls/ChoiceControl.php
+++ b/src/Forms/Controls/ChoiceControl.php
@@ -62,7 +62,7 @@ public function setValue($value)
 				70,
 				'...',
 			);
-			throw new Nette\InvalidArgumentException("Value '$value' is out of allowed set [$set] in field '{$this->name}'.");
+			throw new Nette\InvalidArgumentException("Value '$value' is out of allowed set [$set] in field '{$this->getName()}'.");
 		}
 
 		$this->value = $value === null ? null : key([(string) $value => null]);
diff --git a/src/Forms/Controls/ColorPicker.php b/src/Forms/Controls/ColorPicker.php
index 0b82a9bd1..22e8f0c28 100644
--- a/src/Forms/Controls/ColorPicker.php
+++ b/src/Forms/Controls/ColorPicker.php
@@ -31,7 +31,7 @@ public function setValue($value): static
 	{
 		if ($value === null) {
 			$this->value = '#000000';
-		} elseif (is_string($value) && preg_match('~#?[0-9a-f]{6}~DAi', $value)) {
+		} elseif (is_string($value) && preg_match('~#?[0-9a-f]{6}~Ai', $value)) {
 			$this->value = '#' . strtolower(ltrim($value, '#'));
 		} else {
 			throw new Nette\InvalidArgumentException('Color must have #rrggbb format.');
@@ -44,7 +44,7 @@ public function loadHttpData(): void
 	{
 		try {
 			parent::loadHttpData();
-		} catch (Nette\InvalidArgumentException $e) {
+		} catch (Nette\InvalidArgumentException) {
 			$this->setValue(null);
 		}
 	}
diff --git a/src/Forms/Controls/HiddenField.php b/src/Forms/Controls/HiddenField.php
index e65185b0c..547c426e5 100644
--- a/src/Forms/Controls/HiddenField.php
+++ b/src/Forms/Controls/HiddenField.php
@@ -49,7 +49,7 @@ public function setValue($value)
 		} elseif ($value instanceof \BackedEnum) {
 			$value = $value->value;
 		} elseif (!is_scalar($value) && !$value instanceof Stringable) {
-			throw new Nette\InvalidArgumentException(sprintf("Value must be scalar or null, %s given in field '%s'.", get_debug_type($value), $this->name));
+			throw new Nette\InvalidArgumentException(sprintf("Value must be scalar or null, %s given in field '%s'.", get_debug_type($value), $this->getName()));
 		}
 
 		if (!$this->persistValue) {
diff --git a/src/Forms/Controls/ImageButton.php b/src/Forms/Controls/ImageButton.php
index 035fcbe0b..c9eedcd7b 100644
--- a/src/Forms/Controls/ImageButton.php
+++ b/src/Forms/Controls/ImageButton.php
@@ -16,8 +16,8 @@
 class ImageButton extends SubmitButton
 {
 	/**
-	 * @param  string  $src  URI of the image
-	 * @param  string  $alt  alternate text for the image
+	 * @param  ?string  $src  URI of the image
+	 * @param  ?string  $alt  alternate text for the image
 	 */
 	public function __construct(?string $src = null, ?string $alt = null)
 	{
diff --git a/src/Forms/Controls/MultiChoiceControl.php b/src/Forms/Controls/MultiChoiceControl.php
index 5ab4cb555..a1aade76e 100644
--- a/src/Forms/Controls/MultiChoiceControl.php
+++ b/src/Forms/Controls/MultiChoiceControl.php
@@ -52,7 +52,7 @@ public function setValue($values)
 		if (is_scalar($values) || $values === null) {
 			$values = (array) $values;
 		} elseif (!is_array($values)) {
-			throw new Nette\InvalidArgumentException(sprintf("Value must be array or null, %s given in field '%s'.", get_debug_type($values), $this->name));
+			throw new Nette\InvalidArgumentException(sprintf("Value must be array or null, %s given in field '%s'.", get_debug_type($values), $this->getName()));
 		}
 
 		$flip = [];
@@ -60,7 +60,7 @@ public function setValue($values)
 			if ($value instanceof \BackedEnum) {
 				$value = $value->value;
 			} elseif (!is_scalar($value) && !$value instanceof \Stringable) {
-				throw new Nette\InvalidArgumentException(sprintf("Values must be scalar, %s given in field '%s'.", get_debug_type($value), $this->name));
+				throw new Nette\InvalidArgumentException(sprintf("Values must be scalar, %s given in field '%s'.", get_debug_type($value), $this->getName()));
 			}
 
 			$flip[(string) $value] = true;
@@ -74,7 +74,7 @@ public function setValue($values)
 				'...',
 			);
 			$vals = (count($diff) > 1 ? 's' : '') . " '" . implode("', '", $diff) . "'";
-			throw new Nette\InvalidArgumentException("Value$vals are out of allowed set [$set] in field '{$this->name}'.");
+			throw new Nette\InvalidArgumentException("Value$vals are out of allowed set [$set] in field '{$this->getName()}'.");
 		}
 
 		$this->value = $values;
diff --git a/src/Forms/Controls/RadioList.php b/src/Forms/Controls/RadioList.php
index 8fe06d3fc..ef6b8586c 100644
--- a/src/Forms/Controls/RadioList.php
+++ b/src/Forms/Controls/RadioList.php
@@ -122,7 +122,7 @@ public function getLabelPart($key = null): Html
 	{
 		$itemLabel = clone $this->itemLabel;
 		return func_num_args()
-			? $itemLabel->setText($this->translate($this->items[$key]))->for($this->getHtmlId() . '-' . $key)
+			? $itemLabel->setText($this->translate($this->getItems()[$key]))->for($this->getHtmlId() . '-' . $key)
 			: $this->getLabel();
 	}
 
diff --git a/src/Forms/Controls/SubmitButton.php b/src/Forms/Controls/SubmitButton.php
index fd7cdc2f7..470486ad8 100644
--- a/src/Forms/Controls/SubmitButton.php
+++ b/src/Forms/Controls/SubmitButton.php
@@ -35,7 +35,7 @@ public function __construct(string|Stringable|null $caption = null)
 	{
 		parent::__construct($caption);
 		$this->control->type = 'submit';
-		$this->setOmitted(true);
+		$this->setOmitted();
 	}
 
 
@@ -59,7 +59,7 @@ public function isSubmittedBy(): bool
 
 	/**
 	 * Sets the validation scope. Clicking the button validates only the controls within the specified scope.
-	 * @param ?iterable<Nette\Forms\Control|Nette\Forms\Container|string>
+	 * @param  ?iterable<Nette\Forms\Control|Nette\Forms\Container|string>  $scope
 	 */
 	public function setValidationScope(?iterable $scope): static
 	{
diff --git a/src/Forms/Controls/TextBase.php b/src/Forms/Controls/TextBase.php
index 0dea850fd..57099a280 100644
--- a/src/Forms/Controls/TextBase.php
+++ b/src/Forms/Controls/TextBase.php
@@ -35,7 +35,7 @@ public function setValue($value)
 		if ($value === null) {
 			$value = '';
 		} elseif (!is_scalar($value) && !$value instanceof Stringable) {
-			throw new Nette\InvalidArgumentException(sprintf("Value must be scalar or null, %s given in field '%s'.", get_debug_type($value), $this->name));
+			throw new Nette\InvalidArgumentException(sprintf("Value must be scalar or null, %s given in field '%s'.", get_debug_type($value), $this->getName()));
 		}
 
 		$this->value = $value;
diff --git a/src/Forms/Form.php b/src/Forms/Form.php
index b3ab21af6..db0ea94ff 100644
--- a/src/Forms/Form.php
+++ b/src/Forms/Form.php
@@ -256,7 +256,7 @@ public function setAction(string|Stringable $url): static
 	/**
 	 * Returns form's action.
 	 */
-	public function getAction(): mixed
+	public function getAction(): string|Stringable
 	{
 		return $this->getElementPrototype()->action;
 	}
@@ -358,7 +358,7 @@ public function removeGroup(string|ControlGroup $name): void
 			$name = array_search($group, $this->groups, strict: true);
 
 		} else {
-			throw new Nette\InvalidArgumentException("Group not found in form '$this->name'");
+			throw new Nette\InvalidArgumentException("Group not found in form '{$this->getName()}'");
 		}
 
 		foreach ($group->getControls() as $control) {
@@ -458,7 +458,7 @@ public function setSubmittedBy(?SubmitterControl $by): static
 	/**
 	 * Returns submitted HTTP data.
 	 */
-	public function getHttpData(?int $type = null, ?string $htmlName = null): mixed
+	public function getHttpData(?int $type = null, ?string $htmlName = null): string|array|Nette\Http\FileUpload|null
 	{
 		if (!isset($this->httpData)) {
 			if (!$this->isAnchored()) {
@@ -470,11 +470,10 @@ public function getHttpData(?int $type = null, ?string $htmlName = null): mixed
 			$this->submittedBy = is_array($data);
 		}
 
-		if ($htmlName === null) {
-			return $this->httpData;
-		}
+		return $htmlName === null
+			? $this->httpData
+			: Helpers::extractHttpData($this->httpData, $htmlName, $type);
 
-		return Helpers::extractHttpData($this->httpData, $htmlName, $type);
 	}
 
 
diff --git a/src/Forms/Helpers.php b/src/Forms/Helpers.php
index 3a2fdb480..5d4eb1e50 100644
--- a/src/Forms/Helpers.php
+++ b/src/Forms/Helpers.php
@@ -66,7 +66,7 @@ public static function extractHttpData(
 	}
 
 
-	private static function sanitize(int $type, $value)
+	private static function sanitize(int $type, $value): string|array|Nette\Http\FileUpload|null
 	{
 		if ($type === Form::DataText) {
 			return is_scalar($value)
diff --git a/src/Forms/Rendering/DefaultFormRenderer.php b/src/Forms/Rendering/DefaultFormRenderer.php
index 34ebcb936..d0fc673a8 100644
--- a/src/Forms/Rendering/DefaultFormRenderer.php
+++ b/src/Forms/Rendering/DefaultFormRenderer.php
@@ -122,7 +122,7 @@ class DefaultFormRenderer implements Nette\Forms\FormRenderer
 
 	/**
 	 * Provides complete form rendering.
-	 * @param  string  $mode  'begin', 'errors', 'ownerrors', 'body', 'end' or empty to render all
+	 * @param  ?string  $mode  'begin', 'errors', 'ownerrors', 'body', 'end' or empty to render all
 	 */
 	public function render(Nette\Forms\Form $form, ?string $mode = null): string
 	{
@@ -522,7 +522,6 @@ public function getWrapper(string $name): Html
 	protected function getValue(string $name): mixed
 	{
 		$name = explode(' ', $name);
-		$data = &$this->wrappers[$name[0]][$name[1]];
-		return $data;
+		return $this->wrappers[$name[0]][$name[1]] ?? null;
 	}
 }
diff --git a/src/Forms/Validator.php b/src/Forms/Validator.php
index 3a9645f21..fa953e791 100644
--- a/src/Forms/Validator.php
+++ b/src/Forms/Validator.php
@@ -372,7 +372,7 @@ public static function validateFileSize(Controls\UploadControl $control, $limit)
 	 * Has file specified mime type?
 	 * @param  string|string[]  $mimeType
 	 */
-	public static function validateMimeType(Controls\UploadControl $control, $mimeType): bool
+	public static function validateMimeType(Controls\UploadControl $control, string|array $mimeType): bool
 	{
 		$mimeTypes = is_array($mimeType) ? $mimeType : explode(',', $mimeType);
 		foreach (static::toArray($control->getValue()) as $file) {