139 interview questions on Javascript for developers (2025)

109 votes4179 runs

48 votes3826 runs4 comments

30 votes3927 runs

13 votes4098 runs

conditionals

Adrienat Mar 30, 2022

12 votes4359 runs

Kahinaat Apr 6, 2022

11 votes4382 runs0 comment

Kahinaat Apr 12, 2022

11 votes4165 runs

spread operator

Kahinaat Jul 19, 2024

11 votes4132 runs2 comments

Kahinaat Apr 6, 2022

10 votes4374 runs

if else conditions

Kahinaat Apr 6, 2022

10 votes4246 runs

10 votes3092 runs

Axelat Sep 4, 2023

10 votes2379 runs3 comments

Jean-marie Cléryat Nov 8, 2023

9 votes2414 runs

Jean-marie Cléryat Jan 4, 2022

8 votes4228 runs

Kahinaat Apr 6, 2022

8 votes2487 runs0 comment

Jean-marie Cléryat Jan 4, 2022

8 votes2408 runs0 comment

Jean-marie Cléryat Jan 4, 2022

7 votes4104 runs0 comment

Kahinaat Mar 29, 2022

7 votes2851 runs

Damienat Sep 4, 2023

7 votes2438 runs

Jean-marie Cléryat Jan 4, 2022

7 votes1634 runs3 comments

Kahinaat Mar 21, 2022

139 interview questions on Javascriptfor developers (2025)

Test your technical skills before an interview of Javascript with 139 corrected questions. Beginner, Intermediate or Expert level.

139 interview questions on Javascriptfor developers (2025)

Test your technical skills before an interview of Javascript with 139 corrected questions. Beginner, Intermediate or Expert level.

Understanding the differences between `map()` and `forEach()` methods in JavaScript

Write a JavaScript function that fetches data from an API and logs it to the console.

Fix the following Javascript loop:

Write a Javascript code that displays 'Adversity is not to be feared' and 'There is potentially a real danger'

The certificate variable is not attainable outside the if loop

What can be said about ECMAScript?

Use spread operator to split an array into two arrays in Javascript

Write a for in loop in Javascript

Write a switch statement that checks if a person can go down a slide based on their weight and height.

Print the number of countries in the array travel.

Find the index of the last element of an array in JavaScript

Write a Javascript code that prints the indexes of an array.

Which of the following equality(s) are true? 0 == '', 'f' + 1 == 'f1'

Filter the elements of an array in Javascript

What will this code display?

Which of the following is the **most optimized** method for creating a literal object?

Add Lyon to the end of the city array

Get the current page URL in Javascript

Invert a string in Javascript

Access the value of the 'level' attribute in a Javascript object

Which of the following is the most optimized method for creating a literal object?