Developer Quizzes

Why Practice with Quizzes?

Active recall through quizzes is one of the most effective ways to retain knowledge. Research shows that testing yourself on material — even before you feel ready — dramatically improves long-term memory compared to passive re-reading.

HTML Quiz

1. Which HTML tag is used to define the main content of a document?
   ✅ <main>
2. What attribute makes an input field required?
   ✅ required
3. Which tag is used for the largest heading?
   ✅ <h1>
4. What does the "href" attribute in an <a> tag specify?
   ✅ The URL of the page the link goes to.

CSS Quiz

1. Which CSS property changes text colour?
   ✅ color
2. How do you centre a block element horizontally?
   ✅ margin: 0 auto; (with a defined width)
3. Which value of position removes an element from the normal document flow?
   ✅ absolute or fixed
4. What does z-index control?
   ✅ The stacking order of overlapping elements.

JavaScript Quiz

1. What does typeof null return?
   ✅ "object" — a famous JavaScript quirk.
2. What is NaN and how do you check for it?
   ✅ NaN means "Not a Number." Check with isNaN(value) or Number.isNaN(value).
3. What does the spread operator (...) do?
   ✅ Expands an iterable (array, string) into individual elements.
4. What is the difference between null and undefined?
   ✅ undefined means a variable was declared but not assigned. null is an intentional absence of value.

CS Fundamentals Quiz

1. What does DNS stand for?
   ✅ Domain Name System
2. Which data structure uses FIFO order?
   ✅ Queue
3. What is O(1) time complexity?
   ✅ Constant time — the operation takes the same time regardless of input size.
4. What is the difference between HTTP and HTTPS?
   ✅ HTTPS is HTTP with TLS/SSL encryption for secure communication.

What's Next?

Review the answers in detail by exploring our full tutorials: HTML, CSS, JavaScript. Or see Interview Q&A for more structured prep.