Question 1

What is asynchronous programming?

Accepted Answer

A programming style where operations are non-blocking and the program continues to run while the operation executes.

Answer

A programming style where operations are blocking and the program waits for the operation to finish.

Answer

A programming style where only one operation can be executed at a time.

Answer

A programming style where the program executes a series of blocking operations.

Question 2

What is the main benefit of using asynchronous programming in JavaScript?

Accepted Answer

To prevent blocking the main thread and improve performance.

Answer

To always make code execution faster.

Answer

To prevent errors from occurring in the main code.

Answer

To replace synchronous programming in all cases.

Question 3

What is a callback function?

Accepted Answer

A function that is passed as an argument to another function and is executed when that function has finished its operation.

Answer

A function that is executed in a loop.

Answer

A function that is executed when an error occurs.

Answer

A function that is called at the beginning of the program.

Question 4

What is the purpose of the setTimeout() function?

Accepted Answer

To delay the execution of a function for a specified amount of time.

Answer

To execute a function immediately.

Answer

To pause the program execution for a specified amount of time.

Answer

To execute a function repeatedly at a specified interval.

Question 5

What is the purpose of the setInterval() function?

Accepted Answer

To repeatedly execute a function at a specified interval.

Answer

To execute a function immediately.

Answer

To delay the execution of a function for a specified amount of time.

Answer

To pause the program execution for a specified amount of time.

Question 6

What is a Promise?

Accepted Answer

An object that represents the eventual completion or failure of an asynchronous operation and its resulting value.

Answer

An object that represents the current state of an asynchronous operation.

Answer

A function that is called immediately.

Answer

A function that is executed repeatedly at a specified interval.

Question 7

What is the purpose of the async keyword?

Accepted Answer

To create an asynchronous function that returns a Promise.

Answer

To make a function execute synchronously.

Answer

To mark a function as deprecated.

Answer

To create a function that returns an Observable.

Question 8

What is the purpose of the await keyword?

Accepted Answer

To pause the execution of an async function until the Promise is resolved.

Answer

To stop the execution of an async function.

Answer

To execute the async function immediately.

Answer

To pass arguments to the async function.

Question 9

What is the difference between a resolved and a rejected Promise in JavaScript?

Accepted Answer

A resolved Promise has successfully finished, while a rejected Promise has encountered an error.

Answer

A resolved Promise only works with callback functions, while a rejected Promise only works with async/await functions.

Answer

A resolved Promise always returns a value, while a rejected Promise does not.

Answer

A resolved Promise is always synchronous, while a rejected Promise is always asynchronous.

Question 10

What is the purpose of the finally() method in JavaScript Promises?

Accepted Answer

To execute code after a Promise has resolved or rejected.

Answer

To execute code only if a Promise has resolved.

Answer

To execute code only if a Promise has rejected.

Answer

To replace the catch() method in all cases.

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