What are React controlled components and uncontrolled components?

When working with React, you may come across the terms “controlled components” and “uncontrolled components”. These concepts refer to different ways of handling form inputs and managing their state within a React application.

Controlled Components

A controlled component is a form element whose value is controlled by React. In other words, React maintains the state of the form input and updates it as the user interacts with it. This allows you to have full control over the input’s value and behavior.

To create a controlled component, you need to provide the value prop to the input element and handle the onChange event to update the value in the component’s state. Here’s an example:

{`import React, { useState } from 'react';

function ControlledComponent() {
  const [value, setValue] = useState('');

  const handleChange = (event) => {
    setValue(event.target.value);
  };

  return (
    
  );
}`}

In the above example, the value of the input is controlled by the value state variable. Whenever the user types in the input, the handleChange function is called, updating the value state and re-rendering the component with the new value.

Uncontrolled Components

On the other hand, an uncontrolled component is a form element whose value is handled by the DOM itself, rather than by React. In this case, React does not control or manage the state of the input.

To create an uncontrolled component, you simply omit the value prop and the onChange event handler. Here’s an example:

{`import React from 'react';

function UncontrolledComponent() {
  return (
    
  );
}`}

In the above example, the input is an uncontrolled component because it does not have a value prop or an onChange event handler. The value of the input will be managed by the browser’s default behavior.

When to Use Controlled or Uncontrolled Components?

The choice between controlled and uncontrolled components depends on your specific use case and requirements.

Controlled components provide more control and flexibility, as you have access to the input’s value and can perform validation or manipulate it before submitting the form. They are recommended when you need to handle form validation, implement complex logic, or synchronize multiple inputs together.

On the other hand, uncontrolled components are simpler to use and require less code. They are suitable for cases where you don’t need to perform any additional logic or validation on the input’s value. Uncontrolled components can be useful for simple forms or when integrating with third-party libraries that manage their own state.

Ultimately, the choice between controlled and uncontrolled components depends on your project’s requirements and your personal preference. React provides the flexibility to use either approach based on your needs.

That’s it for this blog post! We’ve covered the concepts of controlled and uncontrolled components in React. Hopefully, this has helped you understand the differences between the two and when to use each approach in your projects.

Happy coding!

What are React controlled components and uncontrolled components?