OodlesTechnologies React Developer Interview Questions, Process, and Tips

Round duration - 60 minutes
Round difficulty - Easy

Technical round with questions on React mainly.

Q1. What are the differences between functional and class components in React?
Ans. 
Functional components are simpler and easier to test, while class components have more features and lifecycle methods.
• Functional components are written as JavaScript functions, while class components are written as ES6 classes.

• Functional components are stateless and do not have their own internal state, while class components can have state.

• Functional components do not have lifecycle methods, while class components hav...read more
Answered by AI
Add your answer
Q2. What are props in React?
Ans. 
Props are read-only properties passed from a parent component to a child component in React.
• Props allow data to be passed down the component tree.

• Props are immutable and cannot be modified by the child component.

• Props can be used to customize the behavior or appearance of a component.

• Props are accessed using the dot notation, like this.props.propName.

• Props can be any type of data, including strings, numbers, objects, o
Answered by AI
Add your answer
Q3. What is useState() in React?
Ans. 
useState() is a React hook that allows functional components to manage state.
• useState() is used to declare a state variable in a functional component.

• It returns an array with two elements: the current state value and a function to update the state.

• The initial state value is passed as an argument to useState().

• The state can be updated by calling the update function returned by useState().

• useState() can be used multiple ...read more
Answered by AI
Add your answer
Q4. What are custom hooks in React?
Ans. 
Custom Hooks are reusable functions in React that allow you to extract logic from components.
• Custom Hooks are functions that start with the word 'use' and can call other Hooks if needed.

• They are used to share stateful logic between components without using higher-order components or render props.

• Custom Hooks can be used to handle common tasks like fetching data, managing form state, or subscribing to events.

• They promot...read more
Answered by AI
Add your answer

Round duration - 60 minutes
Round difficulty - Easy

Technical round with questions on Javascript mainly. Some output based questions on Javascript were also discussed.

Q1. Can you explain hoisting in JavaScript?
Ans. 
Hoisting is a JavaScript behavior where variable and function declarations are moved to the top of their scope.
• Variable declarations are hoisted but not their initializations.

• Function declarations are fully hoisted.

• Hoisting can lead to unexpected behavior if not understood properly.
Answered by AI
Add your answer
Q2. Does a const variable make the value immutable in JavaScript?
Ans. 
No, const does not make the value immutable.
• const only makes the variable itself immutable, not the value it holds.

• For objects and arrays, const prevents reassignment but allows mutation of properties or elements.

• To make a value truly immutable, you can use Object.freeze() or other techniques.
Answered by AI
View 1 more answer
Q3. What are the states of a promise object in JavaScript?
Ans. 
The states of a promise object are pending, fulfilled, or rejected.
• A promise starts in the pending state.

• When a promise is resolved, it transitions to the fulfilled state.

• If a promise encounters an error, it transitions to the rejected state.

• Once a promise is settled (fulfilled or rejected), it cannot transition to any other state.
Answered by AI
Add your answer

Round duration - 30 minutes
Round difficulty - Easy

HR round with typical Behavioral problems.