Supreme Javascript Test - 63+ MCQs: JavaScript test: Assess Your Knowledge with JavaScript Questions and Answers

1. What is the purpose of the 'bind' method in JavaScript?

To bind an event handler to an element

To create a new array with the results of calling a provided function on every element in the array

To change the value of 'this' in a function

To filter elements in an array

2. Which method is used to remove the last element from an array in JavaScript?

removeLast()

pop()

deleteLast()

splice()

3. What is the purpose of 'console.log()' in JavaScript?

Prints output to the console

Defines a new variable

Creates a loop

Imports a module

4. How do you handle errors in asynchronous JavaScript code?

Using try...catch

Using if...else

Using switch statement

Using for loop

5. Which of the following is a falsy value in JavaScript?

NaN

false

All of the above

6. What is the result of the expression '2 + 2' in JavaScript?

undefined

7. What is the purpose of the 'async' keyword in JavaScript?

To define a synchronous function

To handle exceptions

To indicate that a function returns a promise

To create an asynchronous loop

8. How do you round the number 7.25 to the nearest integer in JavaScript?

Math.round(7.25)

Math.ceil(7.25)

Math.floor(7.25)

round(7.25)

9. How do you write an IF statement in JavaScript?

if (condition) { // code }

if condition: // code

if { // code } condition

condition ? // code : // code

10. What is the purpose of the 'addEventListener()' method in JavaScript?

Attaches an event handler to an element

Adds a new CSS class

Removes an element from the DOM

Creates a new HTML element

11. What is the purpose of 'document.getElementById()' in JavaScript?

Selects an HTML element by its id

Applies styles to an element

Creates a new HTML element

Removes an element from the DOM

12. What does CSS stand for?

Counter Style Sheet

Computer Style Sheet

Colorful Style Sheet

Cascading Style Sheet

13. What is the purpose of 'Array.prototype.filter()' in JavaScript?

Creates a new array with elements passing a test

Removes elements from an array

Sorts the elements of an array

Reverses the elements of an array

14. Which function is used to parse a JSON string in JavaScript?

parseJSON

evalJSON

JSON.parse

parseString

15. How do you create a comment in JavaScript?

// This is a comment

# This is a comment

/* This is a comment */

16. Which operator is used for strict equality in JavaScript?

===

!==

17. What is the purpose of 'setTimeout()' in JavaScript?

Executes a function after a specified time

Pauses the execution of a function

Adds a delay to CSS animations

Sets an interval for a function

18. How do you create an object in JavaScript?

let obj = {}

new Object()

Object.create()

All of the above

19. What is the purpose of 'Promise' in JavaScript?

Handles asynchronous operations

Performs mathematical calculations

Creates an array of elements

Defines a function

20. What is the purpose of the 'fetch' function in JavaScript?

To retrieve data from a server

To delete data from a server

To update data on a server

To send an email

JavaScript MCQ Test 4