Important concepts
| Area | Topics |
|---|---|
| HTML | Semantic HTML, Block vs inline elements, <head>, <script>, <style>, <link>, <form>, <input>, Form validation/submission |
| CSS | Box model, Selectors, Specificity, Positioning, Units, Flexbox, Grid, Media Queries |
| JavaScript | Data types, Scope, Closures, this, Variable declaration (var, let, const), Array methods, Object methods, Promises, Classes, Async/Await |
| DOM | DOM creation/manipulation/traversal, Event bubbling/capturing, Event delegation |
| Runtime APIs | fetch(), Storage (localStorage, sessionStorage), Timers (setTimeout(), setInterval()) |
HTML
| Question | Difficulty |
|---|---|
What is the difference between mouseenter and mouseover event in JavaScript and browsers? | Easy |
Explain the difference between document.querySelector() and document.getElementById() | Easy |
How do <iframe> on a page communicate? Using the postMessage API | Easy |
| How do you add, remove, and modify HTML elements using JavaScript? | Easy |
What is the difference between event.preventDefault() and event.stopPropagation()? | |
What is the difference between innerHTML and textContent? | |
| What is the DOM and how is it structured? |