Which feature do class components have that functional components historically did not, but can be mimicked with hooks?

Which feature do class components have that functional components historically did not, but can be mimicked with hooks?

• A. Automatic batch updates.
• B. Direct access to instance properties.
• C. Class-based rendering.
• D. Lifecycle methods.

Answer: (D)

Lifecycle methods are what class components offer to run code at specific moments in a component’s life—mounting, updating, and unmounting. Functional components didn’t have these hooks by default, since they’re just functions that render. With hooks, you can reproduce that behavior: useEffect runs after render and can be configured to run on mount (empty dependency array), on updates (specific dependencies), or be cleaned up on unmount (the function returned by useEffect). This lets functional components perform the same kinds of side effects you’d place in componentDidMount, componentDidUpdate, and componentWillUnmount in class components.

Lifecycle methods are what class components offer to run code at specific moments in a component’s life—mounting, updating, and unmounting. Functional components didn’t have these hooks by default, since they’re just functions that render. With hooks, you can reproduce that behavior: useEffect runs after render and can be configured to run on mount (empty dependency array), on updates (specific dependencies), or be cleaned up on unmount (the function returned by useEffect). This lets functional components perform the same kinds of side effects you’d place in componentDidMount, componentDidUpdate, and componentWillUnmount in class components.