JS Related UI Developer Interview Questions:

Submitted by: Muhammad
☛ Explain event delegation
☛ Explain how this works in JavaScript
☛ Explain how prototypal inheritance works
☛ What do you think of AMD vs CommonJS?
☛ Explain why the following doesn't work as an IIFE: function foo(){ }();.
☛ What needs to be changed to properly make it an IIFE?
☛ What's the difference between a variable that is: null, undefined or undeclared?
☛ How would you go about checking for any of these states?
☛ What is a closure, and how/why would you use one?
☛ What's a typical use case for anonymous functions?
☛ How do you organize your code? (module pattern, classical inheritance?)
☛ What's the difference between host objects and native objects?
☛ Difference between: function Person(){}, var person = Person(), and var person = new Person()?
☛ What's the difference between .call and .apply?
☛ Explain Function.prototype.bind.
☛ When would you use document.write()?
☛ What's the difference between feature detection, feature inference, and using the UA string?
☛ Explain AJAX in as much detail as possible.
☛ Explain how JSONP works (and how it's not really AJAX).
☛ Have you ever used JavaScript templating?
☛ If so, what libraries have you used?
☛ Explain "hoisting".
☛ Describe event bubbling.
☛ What's the difference between an "attribute" and a "property"?
☛ Why is extending built-in JavaScript objects not a good idea?
☛ Difference between document load event and document ready event?
☛ What is the difference between == and ===?
☛ Explain the same-origin policy with regards to JavaScript.
☛ Make this work:
duplicate([1,2,3,4,5]); // [1,2,3,4,5,1,2,3,4,5]
☛ Why is it called a Ternary expression, what does the word "Ternary" indicate?
☛ What is "use strict";? what are the advantages and disadvantages to using it?
☛ 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
☛ Why is it, in general, a good idea to leave the global scope of a website as-is and never touch it?
☛ Why would you use something like the load event? Does this event have disadvantages? Do you know any alternatives, and why would you use those?
☛ Explain what a single page app is and how to make one SEO-friendly.
☛ What is the extent of your experience with Promises and/or their polyfills?
☛ What are the pros and cons of using Promises instead of callbacks?
☛ What are some of the advantages/disadvantages of writing JavaScript code in a language that compiles to JavaScript?
Submitted by: Muhammad

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