ReactJS Interview Questions

What is ReactJS?

Ans: ReactJS is an open-source JavaScript library used for building reusable components in the view layer of an MVC architecture. It efficiently renders user interfaces using a virtual DOM.

Explain the MVC architecture.

Ans: The Model-View-Controller (MVC) framework separates an application into three main components: Model, View, and Controller. Each component handles specific development aspects, isolating business logic, presentation, and data.

What are the building blocks of React?

Ans: Components: Reusable code blocks that return HTML. so Components are building blocks of React

What is Props and State?

Ans: Props pass data between components, while the state stores local data within a component.

What is Context?

Ans: Passes data through components in a hierarchy.

What is Virtual DOM?

Ans: Lightweight copy of the actual DOM for efficient manipulation.

Explain the difference between props and state.

Ans:

• Props: Used to pass data from one component to another. Immutable.
• State: Local data storage within a component. Mutable (can be modified).

What is the Virtual DOM in React?

Ans: React uses a Virtual DOM—a lightweight copy of the actual DOM.

Allthow it was first level interview on react so he just asked this basic questions only apart from this the project was requed Python(FastAPI) Developer as well so he asked me some basic Questions on Python as well like :

What is Python?

Ans: Python is a high-level, interpreted programming language known for its readability and versatility. It is widely used for web development, data analysis, machine learning, and more.

What are the key features of Python?

Ans:

• Readable and expressive syntax
• Dynamic typing
• Extensive standard library
• Cross-platform compatibility

Explain the difference between lists and tuples in Python.

Ans:

• Lists: Mutable, denoted by square brackets ([]).
• Tuples: Immutable, denoted by parentheses (()).

What is a decorator in Python?

Ans: A decorator is a function that modifies or enhances another function. It is commonly used for adding functionality to existing functions.

How does garbage collection work in Python?

Ans: Python’s garbage collector automatically reclaims memory occupied by objects that are no longer referenced.

As Far as i collect i am getting this question only as it was my entry level interview i hope this helps someone