Javascript Skill Assessment

Written by Coursera • Updated on

Test your JavaScript skills with this quick assessment. Answer 10 multiple-choice questions to get your score, then check the Scoring Guide to find your level and recommended learning path.

Javascript Skill Assessment
Javascript Skill Assessment

JavaScript Programming Quiz

1. What is the output of typeof null?

"null"
"object"
"undefined"
null

2. What's the difference between let, const, and var?

No difference
let and const are block-scoped, var is function-scoped
const cannot be reassigned, let and var can
Both B and C are correct

3. What is the output of this code?

const numbers = [1, 2, 3];
const [, second] = numbers;
console.log(second);
  
[1, 2, 3]
2
undefined
Error

4. What is a closure in JavaScript?

A way to close browser windows
A function that has access to variables in its outer scope
A method to end a loop
A way to close database connections

5. What is the output of this Promise code?

Promise.resolve(1)
  .then(x => x + 1)
  .then(x => { throw new Error('Failed') })
  .catch(err => 1)
  .then(x => x + 1)
  .then(x => console.log(x))
  
1
2
Error
3

6. What is the purpose of the async/await keywords?

To make code run faster
To handle asynchronous operations in a synchronous-looking way
To create web workers
To define classes

7. What does the prototype property do in JavaScript?

Creates a copy of an object
Allows objects to inherit properties and methods
Protects private variables
Defines static methods

8. What is event bubbling?

A way to create new events
Events triggered on a child element bubble up through its parents
A method to stop events
A way to group similar events

9. What is the purpose of the Map object?

To transform arrays
To store key-value pairs where keys can be any type
To create new arrays
To sort data

10. What is the difference between == and ===?

No difference
=== is faster than ==
== performs type coercion, === does not
=== works only with numbers

Scoring Guide & Course Recommendations

0-30: Beginner Level

40-70: Intermediate Level

80-100: Advanced Level

Skills Covered by Level

Beginner Level

  • Variables and data types

  • Control structures

  • Basic functions

  • DOM manipulation

  • Event handling

  • Basic arrays and objects

Intermediate Level

  • ES6+ features

  • Promises and async/await

  • Object-oriented programming

  • Functional programming concepts

  • Error handling

  • Module systems

Advanced Level

  • Design patterns

  • Performance optimization

  • Security best practices

  • Testing and debugging

  • Build tools and bundlers

  • Framework architecture

Career Paths

  • Beginner Level: Junior JavaScript Developer, Frontend Developer Assistant, Web Developer Intern

  • Intermediate Level: JavaScript Developer, Frontend Developer, React/Vue/Angular Developer

  • Advanced Level: Senior JavaScript Developer, Frontend Architect, Technical Lead

Updated on
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Coursera

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