Front End Development Front End Development Frameworks & State Management

Question 1

In React, what is the purpose of the useState hook?

Accepted Answer

To add local state to a functional component

Answer

The useState hook allows functional components to declare and update local state variables, triggering re-renders when state changes.

Question 2

What is the virtual DOM in React?

Accepted Answer

A lightweight in-memory representation of the real DOM used to optimize updates

Answer

React's virtual DOM is an in-memory object tree that React uses to diff against the real DOM and apply only the minimal necessary changes.

Question 3

In Vue.js, which directive conditionally renders an element by toggling its display property?

Accepted Answer

v-show

Answer

v-show toggles an element's CSS display property without removing it from the DOM, unlike v-if which adds/removes the element entirely.

Question 4

What is the purpose of Redux in a React application?

Accepted Answer

To manage and centralize application state

Answer

Redux provides a centralized store for application state, making state predictable and easier to debug across large React applications.

Question 5

In Angular, what is a service used for?

Accepted Answer

Sharing data and business logic across multiple components

Answer

Angular services are singleton classes used to share data, logic, and functionality across components via dependency injection.

Front End Development Practice Test