Practice by framework

Questions List

• Describe the difference between `<script>`, `<script async>` and `<script defer>`

  Importance

  High

  Topics

  HTMLJAVASCRIPT

  Users completed

  1613 completed
• Explain how prototypal inheritance works

  Importance

  High

  Topics

  JAVASCRIPT

  Users completed

  1143 completed
• Explain how `this` works in JavaScript

  Importance

  High

  Topics

  JAVASCRIPT

  Users completed

  1078 completed
• What are the differences between variables created using `let`, `var` or `const`?

  Importance

  High

  Topics

  JAVASCRIPT

  Users completed

  1139 completed
• What is the difference between `==` and `===`?

  Importance

  High

  Topics

  JAVASCRIPT

  Users completed

  1130 completed
• What's the difference between a variable that is: `null`, `undefined` or undeclared?

  Importance

  High

  Topics

  JAVASCRIPT

  Users completed

  993 completed
• What's the difference between `.call` and `.apply`?

  Importance

  High

  Topics

  JAVASCRIPT

  Users completed

  985 completed
• Describe the difference between a cookie, `sessionStorage` and `localStorage`.

  Importance

  High

  Topics

  HTMLJAVASCRIPT

  Users completed

  1114 completed
• Can you offer a use case for the new arrow => function syntax?

  Importance

  High

  Topics

  JAVASCRIPT

  Users completed

  9 completed
• Describe event bubbling

  Importance

  High

  Topics

  JAVASCRIPTHTML

  Users completed

  908 completed
• Explain event delegation

  Importance

  High

  Topics

  JAVASCRIPTHTML

  Users completed

  865 completed
• Explain `Function.prototype.bind`

  Importance

  High

  Topics

  JAVASCRIPT

  Users completed

  790 completed
• Explain "hoisting"

  Importance

  High

  Topics

  JAVASCRIPT

  Users completed

  828 completed
• Explain the difference between synchronous and asynchronous functions

  Importance

  High

  Topics

  JAVASCRIPT

  Users completed

  749 completed
• What are the pros and cons of using Promises instead of callbacks?

  Importance

  High

  Topics

  JAVASCRIPT

  Users completed

  691 completed
• What is a closure, and how/why would you use one?

  Importance

  High

  Topics

  JAVASCRIPT

  Users completed

  673 completed
• What is event loop?

  Importance

  High

  Topics

  JAVASCRIPT

  Users completed

  670 completed
• What language constructions do you use for iterating over object properties and array items?

  Importance

  High

  Topics

  JAVASCRIPT

  Users completed

  9 completed
• What's a typical use case for anonymous functions?

  Importance

  High

  Topics

  JAVASCRIPT

  Users completed

  655 completed
• Difference between: `function Person(){}`, `var person = Person()`, and `var person = new Person()`?

  Importance

  Mid

  Topics

  JAVASCRIPT

  Users completed

  412 completed
• Explain Ajax in as much detail as possible.

  Importance

  Mid

  Topics

  JAVASCRIPTNETWORK

  Users completed

  396 completed
• Explain how JSONP works (and how it's not really Ajax)

  Importance

  Mid

  Topics

  JAVASCRIPTNETWORKSECURITY

  Users completed

  296 completed
• Explain the difference between mutable and immutable objects

  Importance

  Mid

  Topics

  JAVASCRIPT

  Users completed

  323 completed
• Explain the differences on the usage of `foo` between `function foo() {}` and `var foo = function() {}`

  Importance

  Mid

  Topics

  JAVASCRIPT

  Users completed

  365 completed
• Explain what a single page app is and how to make one SEO-friendly

  Importance

  Mid

  Topics

  JAVASCRIPT

  Users completed

  333 completed
• What advantage is there for using the arrow syntax for a method in a constructor?

  Importance

  Mid

  Topics

  JAVASCRIPT

  Users completed

  286 completed
• What are the differences between ES2015 class and ES5 function constructors?

  Importance

  Mid

  Topics

  JAVASCRIPT

  Users completed

  276 completed
• What is the definition of a higher-order function?

  Importance

  Mid

  Topics

  JAVASCRIPT

  Users completed

  316 completed
• What is `"use strict";`?

  Importance

  Mid

  Topics

  JAVASCRIPT

  Users completed

  304 completed
• What's the difference between an "attribute" and a "property"?

  Importance

  Mid

  Topics

  JAVASCRIPT

  Users completed

  292 completed
• What's the difference between feature detection, feature inference, and using the UA string?

  Importance

  Mid

  Topics

  JAVASCRIPT

  Users completed

  227 completed
• Why is it, in general, a good idea to leave the global scope of a website as-is and never touch it?

  Importance

  Mid

  Topics

  JAVASCRIPT

  Users completed

  269 completed
• Can you describe the main difference between a `.forEach` loop and a `.map()` loop?

  Importance

  Low

  Topics

  JAVASCRIPT

  Users completed

  282 completed
• Can you give an example for destructuring an object or an array?

  Importance

  Low

  Topics

  JAVASCRIPT

  Users completed

  258 completed
• Can you give an example of a curry function and why this syntax offers an advantage?

  Importance

  Low

  Topics

  JAVASCRIPT

  Users completed

  184 completed
• Create a for loop that iterates up to `100` while outputting **"fizz"** at multiples of `3`, **"buzz"** at multiples of `5` and **"fizzbuzz"** at multiples of `3` and `5`

  Importance

  Low

  Topics

  JAVASCRIPT

  Users completed

  208 completed
• Difference between document `load` event and document `DOMContentLoaded` event?

  Importance

  Low

  Topics

  JAVASCRIPT

  Users completed

  201 completed
• ES2015 Template Literals offer a lot of flexibility in generating strings, can you give an example?

  Importance

  Low

  Topics

  JAVASCRIPT

  Users completed

  201 completed
• Explain the same-origin policy with regards to JavaScript

  Importance

  Low

  Topics

  JAVASCRIPTNETWORK

  Users completed

  213 completed
• Explain why the following doesn't work as an IIFE: `function foo(){ }();`. What needs to be changed to properly make it an IIFE?

  Importance

  Low

  Topics

  JAVASCRIPT

  Users completed

  202 completed
• How can you share code between files?

  Importance

  Low

  Topics

  JAVASCRIPT

  Users completed

  204 completed
• How do you organize your code?

  Importance

  Low

  Topics

  JAVASCRIPT

  Users completed

  187 completed
• What are some of the advantages/disadvantages of writing JavaScript code in a language that compiles to JavaScript?

  Importance

  Low

  Topics

  JAVASCRIPT

  Users completed

  178 completed
• What are the advantages and disadvantages of using Ajax?

  Importance

  Low

  Topics

  JAVASCRIPTNETWORK

  Users completed

  181 completed
• What are the benefits of using spread syntax and how is it different from rest syntax?

  Importance

  Low

  Topics

  JAVASCRIPT

  Users completed

  208 completed
• What do you think of AMD vs CommonJS?

  Importance

  Low

  Topics

  JAVASCRIPT

  Users completed

  161 completed
• What is the extent of your experience with Promises and/or their polyfills?

  Importance

  Low

  Topics

  JAVASCRIPT

  Users completed

  185 completed
• What tools and techniques do you use for debugging JavaScript code?

  Importance

  Low

  Topics

  JAVASCRIPT

  Users completed

  221 completed
• What's the difference between host objects and native objects?

  Importance

  Low

  Topics

  JAVASCRIPT

  Users completed

  199 completed
• When would you use `document.write()`?

  Importance

  Low

  Topics

  JAVASCRIPT

  Users completed

  189 completed
• Why is extending built-in JavaScript objects not a good idea?

  Importance

  Low

  Topics

  JAVASCRIPT

  Users completed

  210 completed
• Why is it called a Ternary expression, what does the word "Ternary" indicate?

  Importance

  Low

  Topics

  JAVASCRIPT

  Users completed

  265 completed
• Why would you use something like the `load` event?

  Importance

  Low

  Topics

  JAVASCRIPT

  Users completed

  217 completed
• Why you might want to create static class members?

  Importance

  Low

  Topics

  JAVASCRIPT

  Users completed

  228 completed