In the world of web development, JavaScript stands as one of the most sought-after skills for job seekers. Whether you're applying for a junior frontend developer role or a full-stack engineer position, you’ll likely face JavaScript-based technical interviews and online MCQ exams.
To succeed, it's crucial to understand not just how JavaScript works—but why it behaves the way it does.
Before diving into practice questions, let’s explore the most frequently asked JavaScript concepts in coding assessments and interviews:
var, let, constKnow the differences in scope, hoisting, and mutability.
let x = 10;
const y = 20;
var z = 30;
Understand function and block scope, as well as how closures retain access to variables even after their parent function has executed.
function outer() {
let count = 0;
return function inner() {
count++;
return count;
}
}
setTimeout, Promises, Async/AwaitThese are critical for handling network requests and time-based events.
async function fetchData() {
const data = await fetch('https://api.example.com');
return data.json();
}
Why does console.log(a) return undefined when declared with var, but throw an error with let?
this KeywordHow this behaves differently in functions, arrow functions, and class methods.
Understand object linking and how inheritance works in JavaScript.
function Animal(name) {
this.name = name;
}
Animal.prototype.speak = function () {
return `${this.name} makes a sound`;
};
Crucial for writing non-blocking code and understanding execution timing.
Multiple-choice questions test not just theory but also your ability to differentiate similar concepts, identify edge cases, and make quick decisions—just like real interviews do.
On JavaScript-Exam.com, you get:
What is the result of the following code?
console.log(typeof null);
Options:
nullobject ✅undefinedbooleanExplanation: Despite being a primitive type, typeof null returns 'object' due to a legacy bug in JavaScript.
Here’s why developers love this tool:
Here’s a 5-step strategy to make the most out of your prep time:
🚀 Tip: Group questions by topic (like async/await or event bubbling) for focused revision.
Whether you're a beginner or a seasoned developer, this platform is designed for:
JavaScript interview prep doesn’t need to be overwhelming. By focusing on key concepts and consistent MCQ practice, you can:
Start practicing today at 👉 JavaScript-Exam.com and take control of your career path.
JavaScript-Exam.com is interview-focused, ad-free, and tailored for serious learners preparing for real-world scenarios.
Absolutely! With unlimited test attempts and ever-growing question banks, it’s perfect for daily use.
No. The platform is 100% free—no subscriptions, no paywalls.
Yes! The entire site is mobile responsive, so you can prep anywhere.
Ready to ace your next JavaScript interview? 👉 Head over to JavaScript-Exam.com and start now — no sign-up required!