ReactJS Q & A


What is an uncontrolled component?

In React, an uncontrolled component refers to a form element whose value is managed by the DOM itself, rather than by the React component’s state. Unlike controlled components, where React holds the single source of truth for input values, uncontrolled components entrust this responsibility to the DOM.

The primary distinction of uncontrolled components lies in their reliance on refs to directly access the form elements. Instead of binding an input’s value to a piece of state and using event handlers to update that state, you’d use a ref to retrieve the current value from the DOM when needed. This is reminiscent of traditional JavaScript or jQuery approaches, where you’d directly query the DOM element to obtain or manipulate its value.

There are scenarios where uncontrolled components can be beneficial:

  1. When integrating React with non-React code that relies on the direct DOM value.
  2. In situations where trying to control every input might be overkill or lead to unnecessary complexity.
  3. When form validation and submission do not require real-time data processing or feedback.

However, the trade-off is that you’re bypassing the typical React data flow. While this might simplify the code in some scenarios, it might also make the component behavior less predictable, especially in larger applications where data flow consistency is crucial.

It’s worth noting that while React emphasizes controlled components due to the advantages they offer in terms of consistency and data flow management, there are valid use-cases for uncontrolled components. React even provides certain tools, like the `defaultValue` prop for inputs, to better support them.

Uncontrolled components in React represent a hands-off approach to form management, letting the DOM hold the reins. While they can simplify certain scenarios, understanding when to use them versus controlled components is key to crafting efficient and maintainable React applications.