JavaScript and React Quiz

Which of the following statements about React is true?

• React is a backend framework.

• React requires Babel to function.

• React manipulates the DOM directly.

• React is only for server-side rendering.

What will be logged? const user = { name: "John", age: 30 }; const { name } = user; console.log(name);

• undefined

• John

• { name: "John" }

• 30

Which HTTP method is commonly used for updating a resource?

• GET

• POST

• PUT

• DELETE

What will be the output of the following code? let x = 10; function modify() { x = 20; } modify(); console.log(x);

• 10

• 20

• undefined

• ReferenceError

What is the purpose of the useState hook in React?

• To manage component side effects

• To handle API requests

• To create and manage state in functional components

• To define routes

What does the finally() method do in JavaScript Promises?

• Runs only if the promise resolves successfully

• Runs only if the promise rejects

• Runs regardless of the promise state

• Cancels a pending promise

What is an advantage of using Axios over the Fetch API?

• Fetch supports request cancellation, while Axios does not

• Axios automatically parses JSON responses

• Fetch supports interceptors, while Axios does not

• Fetch works only in modern browsers

What will be logged? console.log(typeof null);

• "null"

• "undefined"

• "object"

• "number"

Which of the following methods is used to run a function once after a delay?

• setInterval()

• setTimeout()

• delay()

• wait()

What is the primary purpose of Jest in JavaScript?

• API management

• Front-end rendering

• Unit testing

• Database queries