IMPACT Infotech React Js Software Engineer Interview Questions and Answers

Reconciliation is the process of updating the UI to match the current state of the application.

• Reconciliation is the algorithm used by React to update the DOM efficiently.

• It compares the virtual DOM with the actual DOM and only updates the parts that have changed.

• Reconciliation is a key feature of React that helps in optimizing performance.

• Examples include adding, removing, or updating elements in a list without re-ren

useMemo is a hook used for memoization of expensive calculations, while react.memo is a higher order component used for memoizing functional components.

• useMemo is used to memoize expensive calculations and can be used inside functional components.

• react.memo is used to memoize functional components to prevent unnecessary re-renders.

• useMemo returns a memoized value, while react.memo returns a memoized component.

• Example: ...read more