Top React JS Interview Questions for Freshers
- What is React JS, and how does it work?
- What is the virtual DOM, and how is it different from the real DOM?
- What are components in React? Explain functional vs class components.
- What is JSX, and why is it used in React?
- Explain the difference between props and state.
- What are React Hooks? Name a few commonly used ones.
- How does the useState hook work?
- What is the purpose of useEffect in React?
- What is the significance of keys in a list?
- What are controlled and uncontrolled components in React?
These React JS interview questions for freshers test your basic understanding and are often used to evaluate your ability to build simple, functional UI components. Focus more on concepts than memorized answers—understanding is key.
Quick Tips to Crack a React JS Interview
Want to stand out in your first React JS interview? Follow these quick tips to boost your chances of cracking the most common React JS Interview Questions for Freshers:
✅ Master the Basics: Before diving into complex topics, make sure you’re solid on the fundamentals. Most React JS Interview Questions for Freshers focus on core concepts like JSX, components, props, state, and beginner-level hooks like
useStateanduseEffect.✅ Build Small Projects: Create simple applications like a to-do list, weather app, or calculator. Having hands-on experience helps you confidently answer practical React JS Interview Questions for Freshers. Don’t forget to upload your work to GitHub—interviewers love to see real code.
✅ Explain Code Clearly: Many React JS Interview Questions for Freshers revolve around your ability to communicate your logic. Practice explaining how your code works, especially in areas like state management and component rendering.
✅ Practice Live Coding: Familiarize yourself with platforms like CodeSandbox or StackBlitz. Freshers often face live coding React JS interview questions, and real-time problem-solving can set you apart.
✅ Read the Docs: The official React documentation is a goldmine. Many React JS Interview Questions for Freshers are inspired by what’s in the docs. It’s clear, beginner-friendly, and always up to date.
Recommended Resources to Prepare
To help you confidently tackle React JS interview questions for freshers, here are some high-quality (and often free) resources:
- 📘 React Official Docs: react.dev – The best place to learn React fundamentals.
- 📺 YouTube Channels:
- Codevolution (great for React tutorials)
- Web Dev Simplified
- freeCodeCamp
- 📚 Free Courses:
- React Basics on Scrimba
- freeCodeCamp’s Frontend Libraries Certification
- 👨💻 Practice Platforms:
- Frontend Mentor
- CodeSandbox
- LeetCode – for JS logic and data structures
- 📘 Books:
- The Road to React by Robin Wieruch (great for beginners)
- Fullstack React (for advanced growth)
Start with official docs, then build small apps, and finally, test your skills with mock interviews.
Most Common React JS Interview Mistakes to Avoid
Freshers often make avoidable mistakes during React interviews. Here are some of the most common pitfalls:
- ❌ Confusing Props and State: Many freshers mix up where to use props vs. state. Props are read-only and passed down; state is mutable and managed within the component.
- ❌ Overusing Hooks Without Understanding: Using useEffect or useState blindly without understanding lifecycle behavior is a red flag.
- ❌ Ignoring the Virtual DOM Concept: Be prepared to explain how React’s virtual DOM improves performance.
- ❌ Not Explaining Thought Process: It’s okay to not know everything—what matters is how you think through a problem.
- ❌ Skipping Small Projects: Talking theory without building anything makes it harder to prove your understanding.
If you’re targeting React JS interview questions for freshers, make sure your basics are clear and you can apply them in code.
React Hooks Interview Questions for Freshers
🔄 React Hooks Interview Questions for Freshers
Hooks are a crucial topic in modern React interviews. Here are the most common React JS interview questions for freshers related to Hooks:
- What are React Hooks?
- What’s the purpose of useState? Can you give an example?
- Explain how useEffect works and its dependency array.
- What is the difference between useEffect and componentDidMount?
- What is the use of useRef in React?
- Can you call hooks inside loops or conditionals? Why or why not?
- What is the rules of hooks?
- When would you use useContext over prop drilling?
Hooks are now the standard in React, so it’s important to be fluent with the basics like useState, useEffect, and optionally, useContext.
JSX and Virtual DOM – Frequently Asked Questions
Understanding JSX and the virtual DOM is essential to answer conceptual React JS interview questions for freshers. Here’s how you can approach these:
📌 What is JSX?
JSX (JavaScript XML) is a syntax extension that lets you write HTML-like code in JavaScript. It makes your UI code more readable and declarative. Example:
jsx
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const element = <h1>Hello, React!</h1>;
This gets compiled into React.createElement(…) behind the scenes.
📌 What is the Virtual DOM?
The virtual DOM is a lightweight copy of the real DOM. React uses it to detect what’s changed and updates only the parts of the real DOM that need to change — making updates fast and efficient.
Common Questions:
- How does JSX differ from HTML?
- Why does React need a virtual DOM?
- Can we write React without JSX?
- What happens behind the scenes when JSX is compiled?
Explaining these clearly shows you understand React’s core performance features and syntax.