Controlled Components
Controlled components are a pattern in React where form data is handled by the component's state, making React the single source of truth for the input values. The component's state is updated via event handlers like onChange, and the input value is set directly from the state, ensuring predictable behavior and enabling validation or transformation of user input. This approach contrasts with uncontrolled components, where form data is managed by the DOM itself.
Developers should use controlled components when they need full control over form inputs, such as for real-time validation, dynamic form behavior, or integrating with state management libraries like Redux. It's essential in applications requiring complex form logic, such as multi-step wizards, conditional fields, or when input values must be synchronized across components, as it ensures data consistency and simplifies debugging by centralizing state management.