What is the primary difference between controlled and uncontrolled components in React forms?
Controlled components rely on React's state management for form data, while uncontrolled components use DOM references.
Controlled components are suitable for simple forms, while uncontrolled components are ideal for complex forms.
Controlled components are deprecated in React, and uncontrolled components are the recommended approach.
Controlled components directly manipulate the DOM, while uncontrolled components use React's state management.
How do you define default props for a functional component in React?
Using the defaultProps property of the component function
defaultProps
By passing them as arguments to the component
Default props are not supported for functional components
Inside the component's function body
What's a common way to bind event handlers in React class components?
Using arrow functions in the render method
render
Calling addEventListener within the componentDidMount lifecycle method
addEventListener
componentDidMount
Using bind in the constructor
bind
Both 'Using bind in the constructor' and 'Using arrow functions in the render method'
What is the primary use case for the useEffect hook?
useEffect
To perform side effects like data fetching, DOM manipulation, or subscriptions
To render components conditionally
To handle form submissions
To manage state within a component
In React functional components, how do you typically handle events?
Using inline event handlers directly in JSX
By creating separate event listener functions outside the component
By defining methods inside the component class
Events are not handled in functional components, only in class components
Which type of component in React is primarily used for presenting data and does not manage its own state?
State Component
Higher-Order Component
Class Component
Functional Component
What is the recommended approach for handling events in React class components?
Use global event listeners to manage events outside the component
Define event handlers as separate methods within the class and bind them in the constructor
Define event handlers as inline arrow functions within the render method
Event handling is not typically done within React class components
Which of the following is a common approach for implementing form validation in React?
Using HTML5 form validation attributes.
Writing custom validation functions within the component.
Utilizing a dedicated form validation library.
All of the above.
When would it be more appropriate to consider using an uncontrolled component in a React form?
When integrating with a third-party library that requires direct access to form elements.
When you prefer a more imperative approach and direct DOM manipulation.
When you need real-time validation and immediate feedback to the user.
When dealing with a large, complex form where performance optimization is critical.
What will happen if you update the state directly in a React component?
Nothing will happen; the state will remain unchanged.
An error will be thrown, and the application will crash.
The component will re-render, but the state change won't be reflected.
The component will re-render, and the state change will be reflected correctly.