A while ago, a group of very intelligent and experienced Front-end Developers got together and created a list of great Front-end focused job interview questions. This group consisted of @bentruyman,@ajpiano, @paul_irish, @SlexAxton, @boazsender, @miketaylr, @iansym, @vladikoff and @gf3. Since it’s creation, I’ve expanded to this list and happen to use it to help friends prepare for interviews (like my good friend Wes Bos / @wesbos) or to interview developers myself.

To note, I think that it’s only necessary to choose a handfull of questions from this list to get a good sense of a candidates capabilities and fit. The most telling questions often relate to what a person does in their free time. Asking about Twitter & Github Accounts, RSS feeds, Personal Blogs and general community involvement will tell you a lot about whether or not this person will stay up-to-date and is passionate about their work. The last group of questions will definitely let you know if the person’s got a sense of humour.

Hope this list helps some people and, if you do use it, make sure to give credit to the folks that contributed (listed above).

Note: I’ve posted this document up on Github so that you can add to it if you want. Here’s the link: https://github.com/darcyclarke/Front-end-Developer-Interview-Questions

JOB INTERVIEW QUESTIONNAIRE

General Questions:

  • Are you on Twitter?
    • If so, who do you follow on Twitter?
  • Are you on Github?
    • If so, what are some examples of repos you follow
  • What blogs do you follow?
  • What version control systems have you used?
  • What is your preferred development enviroment? (OS, Editor, Browsers, Tools etc.)
  • Can you describe your workflow when you create a web page?
  • Can you describe the difference between progressive enhancement and graceful degradation?
    • Bonus points for the answer “no one can”
    • Extra bonus points for describing feature detection
  • Explain what “Semantic HTML” means.
  • What does “minification” do?
  • Why is it better to serve site assets from multiple domains? 
    • How many resources will a browser download from a given domain at a time?
  • If you have 8 different stylesheets for a given design, how would you integrate them into the site?
    • Looking for file concatenation.
    • Points off for @import, unless it works in conjunction with a build system.
  • If you jumped on a project and they used tabs and you used spaces, what would you do?
    • issue :retab! command
  • Write a simple slideshow page
    • Bonus points if it does not use JS.
  • What tools do you use to test your code’s performance?
  • If you could master one technology this year, what would it be?
  • Name 3 ways to decrease page load. (perceived or actual load time)
  • Explain the importance of standards.

HTML-Specific Questions:

  • What’s a doctype do, and how many can you name?
  • What’s the difference between standards mode and quirks mode?
  • What are the limitations when serving XHTML pages?
    • Are there any problems with serving pages as application/xhtml+xml?
  • How do you serve a page with content in multiple languages?
  • Can you use XHTML syntax in HTML5? How do you use XML in HTML5?
  • What are data- attributes good for?
  • What are the content models in HTML4 and are they different in HTML5?
  • Consider HTML5 as an open web platform. What are the building blocks of HTML5?
  • Describe the difference between cookies, sessionStorage and localStorage.

JS-Specific Questions

  • Which JavaScript libraries have you used?
  • How is JavaScript different from Java?
  • What are undefined and undeclared variables?
  • What is a closure, and how/why would you use one?
    • Your favorite pattern used to create them? argyle (Only applicable to IIFEs)
  • What’s a typical use case for anonymous functions?
  • Explain the “JavaScript module pattern” and when you’d use it.
    • Bonus points for mentioning clean namespacing.
    • What if your modules are namespace-less?
  • 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()
    		var person = new Person()
    	
  • What’s the difference between .call and .apply?
  • explain Function.prototype.bind?
  • When do you optimize your code?
  • Can you explain how inheritance works in JavaScript?
    • Bonus points for the funny answer: “no one can”
    • Extra bonus points if they take a stab at explaining it
  • When would you use document.write()?
    • Correct answer: 1999 – time to weed out the junior devs
  • 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, and if so, what/how?
  • Explain “hoisting”.
  • What is FOUC? How do you avoid FOUC?
  • Describe event bubbling.
  • What’s the difference between an “attribute” and a “property”?
  • Why is extending built in JavaScript objects not a good idea?
  • Why is extending built ins a good idea?
  • Difference between document load event and document ready event?
  • What is the difference between == and ===?
  • Explain how you would get a query string parameter from the browser window’s URL.
  • Explain the same-origin policy with regards to JavaScript.
  • Explain event delegation.
  • Describe inheritance patterns in JavaScript.
  • Make this work: 
    [1,2,3,4,5].duplicator(); // [1,2,3,4,5,1,2,3,4,5]
  • Describe a strategy for memoization in JavaScript.
  • Why is it called a Ternary statement, what does the word “Ternary” indicate?
  • What is the arity of a function?

JS-Code Examples:

~~3.14

Question: What value is returned from the above statement?
Answer: 3

"i'm a lasagna hog".split("").reverse().join("");

Question: What value is returned from the above statement?
Answer: “goh angasal a m’i”

( window.foo || ( window.foo = "bar" ) );

Question: What is the value of window.foo?
Answer: “bar”

var foo = "Hello";
(function() { 
  var bar = " World"; 
  alert(foo + bar); 
})(); 
alert(foo + bar);

Question: What is the outcome of the two alerts above?
Answer: ”Hello World” & ReferenceError: bar is not defined

jQuery-Specific Questions:

  • Explain “chaining”.
  • What does .end() do?
  • How, and why, would you namespace a bound event handler?
  • What is the effects (or fx) queue?
  • What is the difference between .get(), [], and .eq()?
  • What is the difference between .bind(), .live(), and .delegate()?
  • What is the difference between $ and $.fn? Or just what is $.fn.
  • Optimize this selector:
    $(".foo div#bar:eq(0)")

CSS-Specific Questions:

  • Describe what a “reset” CSS file does and how it’s useful.
  • Describe Floats and how they work.
  • What are the various clearing techniques and which is appropriate for what context?
  • Explain CSS sprites, and how you would implement them on a page or site.
  • What are the differences between the IE box model and the W3C box model?
  • What are your favourite image replacement techniques and which do you use when?
  • CSS property hacks, conditionally included .css files, or… something else?
  • How do you serve your pages for feature-constrained browsers?
    • What techniques/processes do you use?
  • What are the different ways to visually hide content (and make it available only for screenreaders)?
  • Have you ever used a grid system, and if so, what do you prefer?
  • Hav you used or implement media queries or mobile specific layouts/CSS? 
  • Any familiarity with styling SVG?
  • How do you optimize your webpages for print?
  • What are some of the “gotchas” for writing efficient CSS?
  • Do you use LESS?
  • How would you implement a web design comp that uses non-standard fonts? (avoid mentioning webfonts so they can figure it out)
  • Explain how a browser determines what elements match a CSS selector?

Optional fun Questions:

  • What’s the coolest thing you’ve ever coded, what are you most proud of?
  • Do you know the HTML5 gang sign?
  • Are you now, or have you ever been, on a boat.
  • Tell me your favorite parts about Firebug / Webkit Inspector.
  • Do you have any pet projects? What kind?
  • Explain the significance of “cornify”.
  • On a piece of paper, write down the letters A B C D E vertically. Now put these in descending order without writing one line of code.
    • Wait and see if they turn the paper upside down
    • This should make the laugh and is a fine way to relieve some tension at the end of the interview.
  • Pirate or Ninja?
    • bonus if it’s a combo and a good reason was given (+2 for zombie monkey pirate ninjas)
    • If not Web Development what would you be doing?
    • Where in the world is Carmen Sandiego?
      • (hint: their answer is always wrong)
    • What’s your favorite feature of Internet Explorer?

87 Comments

Alex Posted: Feb 09, 2012 @ 11:14pm

Some of these are good.

Iain Dooley Posted: Feb 09, 2012 @ 11:34pm

I’ll remember this next time I’m trying to hire a superhuman aggregate of 11 of the smartest UX/frontend people on the planet ;)

In all seriousness, though, it’s a great list of what defines good frontend development, thanks for posting.

Greg Guida Posted: Feb 10, 2012 @ 12:42am

The proper answer to “What is the value of ~~3.14″ is..
DONT EVER USE THAT IN PRODUCTION CODE

Stevey noname Posted: Feb 10, 2012 @ 6:44am

**Their** answer is always wrong.

James Posted: Feb 10, 2012 @ 12:21pm

> Why is extending built in JavaScript objects not a good idea?
> Why is extending built ins a good idea?

Troll level: Master

> What are data- attributes good for?

They’re for pretending that you’re being semantic and within standards when there are probably other viable solutions.

> Are you on Twitter?

FWIW, if this was someone’s opening question I would start to doubt their proficiency as an interviewer.

cancel bubble Posted: Feb 10, 2012 @ 1:24pm

If someone is on Twitter/Github, those should be on the resume so prospective interviewers can check them out beforehand.

I have some questions on some of your questions:

“How do you serve a page with content in multiple languages?”

What’s the answer to this? Where I work, we do localization via the accept-language header and basically, the framework we’re using handles everything, we just have .properties files with different language text that’s served up based on the mentioned header.

“How do you use XML in HTML5?”

Can you explain what you’re looking for here? I’m assuming you’re not inferring xhtml things like always quote your attributes, tags should be well formed, close singleton tags, etc.

What does this mean?

“Make this work:
[1,2,3,4,5].duplicator();”

Are you asking to create the duplicator method? i.e.,

if (!Array.prototype.duplicator) {
Array.prototype.duplicator = function() { … }
}

“Difference between document load event and document ready event?”

Is this asking the difference between DOMContentLoaded and window.onload? Not sure what you mean by document load event.

“Why is it called a Ternary statement, what does the word “Ternary” indicate?”

Dumb question but why do you care as long as they know how it works? Ternary would seem to imply “three”, IMO, but I have no idea what it really means. I love using it, though, one of my favorites for sure.

Optimize this selector:
$(“.foo div#bar:eq(0)”)

$(‘#bar’);
Right? It’s an id so it has to be unique in the page so you don’t need to descend from anything, don’t need to qualify the tag name and there’s only one occurrence.

“What are the various clearing techniques and which is appropriate for what context?”

How are various clearing techniques appropriate for different contexts? I’ve only used one and it seems to have worked everywhere I’ve needed it.

Some interesting questions here, it’d be a fun interview with these.

Jason Posted: Feb 10, 2012 @ 2:20pm

JavaScript inheritance isn’t hard to explain…

Thierry Posted: Feb 10, 2012 @ 11:30pm

> What are the differences between the IE box model and the W3C box model?

What answer would you expect? Because afaik, there is no “IE box model” per se. IE < 6 uses what's called the "broken box model". IE6 does the same, but only in quirks mode. So I'd expect people who do not know about IE5 and use a proper DTD to not understand the question.

It may be better to ask about the "box-sizing" property and its possible values.

Doug Posted: Feb 11, 2012 @ 3:10am

“What’s your favorite feature of Internet Explorer?”

The quit button

Matthew Posted: Feb 11, 2012 @ 1:12pm

@Cancel Bubble – Regarding optimizing the jQuery selector, while the div and :eq(0) are unnecessary, the .foo may not be. On a multi-page site, you might only want to select #bar if it’s a child of .foo. (.foo might be a homepage body class, for instance.) So I would submit $(‘#bar’,’.foo’); as my answer.

Chris Posted: Feb 12, 2012 @ 10:14am

What’s your favorite feature of Internet Explorer?
How fast google.com/chrome loads

[...] Good selection of front-end Job interview questions. I may not agree with all, but at least someone went into the effort of collecting a list I can [...]

Kelly Posted: Feb 14, 2012 @ 2:17am

@Mathew $(‘.foo’).find(‘#bar’);

tiffany Posted: Feb 15, 2012 @ 2:18pm

I am always one to caution against using buzzwords in an interview. For example: until about 5 minutes ago, I had no idea what “hoisting” was.

I *can,* however, explain to you why …

(function() {
var thevariable;
alert(thevariable);
thevariable = ‘the value’;
})();

… is undefined.

Which is more important in day-to-day work?

JR Posted: Feb 16, 2012 @ 2:45pm

These are great, hope you find your unicorn.

Chris Morata Posted: Feb 16, 2012 @ 2:52pm

FRONT-END DEVS ASSEMBLEEEEEEEE

Ian Posted: Feb 16, 2012 @ 3:03pm

Some of these questions are way too specific and in some cases quite arrogant. Oh and with Carmen Sandiego, it’s “their” not “they’re”.

Kyros Posted: Feb 16, 2012 @ 3:16pm

To be honest, I am not a big fan of interrogation-style questions myself… It’s an interview, not an exam!

Some questions like the ones on your list might be useful (only a few, the most important ones for the specific job) but the candidate should be able to demonstrate what they know and what they can do through live samples of work they have done.

If this many technical and specific questions are essential, I think the candidate should be warned about this and you should ask for answers in writing. If I was to go through such an interview as a candidate, and answer all these verbally, I don’t think I ‘d want to take the job at the end.

That’s what I think, anyway…

It’s always good to use some fun questions though! :-)

[...] Front-end Job Interview Questions (darcyclarke.me) [...]

Natalia Ventre Posted: Feb 16, 2012 @ 4:13pm

Pretty long questionnaire, you’d better pay a good salary if you expect such a long interview :D

Regarding “When would you use document.write()?”, can’t I use it as a fallback for CDN hosted JS libraries, you know, to develop offline?

I use LESS, but why don’t you give points for the others CSS pre-processors?

Antoine Bouchard Posted: Feb 16, 2012 @ 4:36pm

Awesome ideas, but it would be nice to have the answers, so I’ll be able to answer them if I have an interview with those questions (and I will learn by the same occasion)

Darcy Clarke Posted: Feb 16, 2012 @ 5:03pm

Appreciate all the feedback guys. I’ve made some adjustments (typos and such). If you guys have any suggestions or think things should be added or changed remember that you can always contribute to this list via the Git repo here: https://github.com/darcyclarke/Front-end-Developer-Interview-Questions

Patrick Posted: Feb 16, 2012 @ 5:49pm

I’ve actually gone through interviews before where I was bombarded by trivia questions such as this. I turned them down as my “resume and career speak for itself (in regards to knowledge)”.

Why do I want this job again ? Posted: Feb 16, 2012 @ 6:06pm

Did the same type of developer design this site ?
I think you might have missed “Can I see some examples of your work ?”
The rest of your bullshit is a two second google for anyone who has better thing to memorize.

Darcy Clarke Posted: Feb 16, 2012 @ 6:28pm

@Patrick that’s great that your resume and career speak for themselves. That said, I think you’re undermining the quality of these questions by calling them “trivia”. There’s some great discussion to be had around any one of these items and your process in thinking about each will tend to weigh heavier then the actual answer.

To reiterate, one last time, I don’t encourage anyone to use this entire list to interview a candidate. I would feel “bombarded” as well if that were the case. My recommendation, to interviewers, is to pick a few points that are relevant, to the type of work the job entails, and have a meaningful discussion around those. Heck, if it were up to me, I’d make sure all interviews were done over beers or coffee. Being a good “fit” with a team is often just as, or more so, important then having the right answers to all the questions.

Darcy Clarke Posted: Feb 16, 2012 @ 6:32pm

@Why do I want this job again ? – Appreciate your acknowledgment of my aging website. The code is less then up-to-date and the design needs work. I’m in the process of redoing it as we speak. If you’d be kind enough to leave a link to your own website, I’d gladly take pointers.

Neil Posted: Feb 17, 2012 @ 1:16am

Do you use Less?

Bonus points if they rant about how Less is inferior to Sass.

Ferran Basora Posted: Feb 17, 2012 @ 3:13am

And what about knowledge about security like XSS ir others. Could be interesting to ask about reaction in front of repetitive tasks.

Jezen Thomas Posted: Feb 17, 2012 @ 4:23am

Bonus points actually, to those that say LESS and SASS are unnecessary complications in the development process, and are both inferior to well-structured, plain CSS.

I was so excited using LESS on a major client project a couple of months ago, but the drawbacks outweighed the benefits. I enjoy that it fixes the need to write out browser prefixes on CSS3 properties repeatedly, but that gain is not worth the drawback of having to compile .less files, whether client-side, server-side or manually.

LESS nesting can cause code over-specificity too..

I bought a copy of J.Snook’s SMACSS, and I think that’s the way forward.

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Wesley Terry Posted: Feb 17, 2012 @ 9:21am

Following these questions on Github should be extra points. I do think it seems a little more like a pop quiz than questions I would want to answer in an interview. That being said, it is a fun pop quiz to test yourself with. Probably great prep before an interview.

Neil Posted: Feb 17, 2012 @ 12:02pm

Jezen, SMACSS is still possible with both Less and Sass. Over-specificity and proper use of both of those tools is the responsibility of the developer. Anything possible in CSS (including clean, concise code) can be done with Less and/or Sass…

Chad Posted: Feb 17, 2012 @ 3:51pm

Thanks Darcy for posting these. I think i need to work a bit more on my javascript Trivia. Anytime you like to interview me over a couple of beers let me know. I’m buying!

Jens Posted: Feb 17, 2012 @ 6:14pm

So far no-one mentioned accessibility. Shouldn’t we also ask things like

– How do you test the accessibility of your site?

– Which HTML would you use to code up a verbal exchange?

– Why is coding for screen readers not enough?

– When would you use “tabindex”?

etc.

[...] Front-end Job Interview Questions – am răspuns corect la un sfert din întrebările despre JavaScript. Html, jQuery sau CSS au fost ușoare. [...]

Steph Posted: Feb 20, 2012 @ 8:44am

I think anyone reading this for a list of questions to ask during their next interview, needs to read this: http://www.randsinrepose.com/archives/2007/02/25/a_glimpse_and_a_hook.html

I wouldn’t want to work at a place that asks this type of question in an interview – a potential employer need to wow me too – not show me how boring they are with a first time meeting.

nice long list though.

hpshelton Posted: Feb 21, 2012 @ 2:42am

Can you name Opera’s built-in web inspector?

[...] Front-end Job Interview Questions Feb 21 Front-end Job Interview Questions [...]

alejandrolechuga Posted: Feb 22, 2012 @ 1:20am

dang I need to study all this stuff before applying a frontend job :S

Marije Posted: Feb 22, 2012 @ 5:13am

Nice! Went through all the questions and think I can answer 60%, really need to improve that :)

Peter Posted: Feb 22, 2012 @ 5:15am

“Write a simple slideshow page (Bonus points if it does not use JS)”

OK, how can this be done without JS to let the user advance/rewind the slides??

Gary Posted: Feb 22, 2012 @ 5:19am

Forget interview questions, this would make a good revision list for even the most hardy professional :D

Andy Posted: Feb 22, 2012 @ 5:24am

Even though I’ve worked as a front-end developer for 12 years, I’m probably not able to answer more than 1/4 of these questions. Thing is, technical questions like these are imho totally irrelevant in a hiring process. The front-end developers single most important task is to tie together the team, communicating well with both the designers, back-end developers, and projects managers. This asks for a skillset that doesn’t necessarily correlate well with being a technical wiz-kid. :)

And, some of the questions above is just not very correct.. Like:

“When would you use document.write()?”

My reply would be; Almost never, but maybe in cases like where the HTML5 Boilerplate use it:

!window.jQuery && document.write(”)

Ok, I probably wouldn’t get the job… :)

Andy Posted: Feb 22, 2012 @ 5:25am

Ok, the code got whacked.. What I was posting was:

[script src="http://ajax.googleapis.com/ajax/libs/jquery/1.6.2/jquery.min.js"][/script]
[script]!window.jQuery && document.write(‘[script src="/js/jquery-1.6.2.min.js"][/script]‘)[/script]

Jake Posted: Feb 22, 2012 @ 6:11am

Where are the answers? Please post

Phil Wareham Posted: Feb 22, 2012 @ 6:14am

- What’s your favorite feature of Internet Explorer?

Chrome Frame.

John Posted: Feb 22, 2012 @ 6:59am

You need to ask questions. about front end files integration with application.

But still informative.

Tárcio Zemel Posted: Feb 22, 2012 @ 7:08am

“What’s your favorite feature of Internet Explorer?” LOL

Deb Posted: Feb 22, 2012 @ 10:15am

This is great! thank you!

Sergey Posted: Feb 22, 2012 @ 2:48pm

best question:
What’s your favorite feature of Internet Explorer?

add on trick question:
which version of ie is your favorite? )

R. B. Posted: Feb 23, 2012 @ 3:10pm

I would walk out of this interview. What a serious list of garbage

RussellUresti Posted: Feb 23, 2012 @ 4:54pm

Not to get picky, but why are you talking about localStorage and sessionStorage under the HTML-specific part? This may be too semantic/pedantic, but those are part of the JavaScript (or ECMAScript) spec, not the HTML spec.

I know you’re referring to “HTML5″ as HTML5/CSS3/JS1.8, but if you’re saying a question is HTML specific, it should be about the HTML part of HTML5.

chimi Posted: Feb 23, 2012 @ 5:54pm

“Can you describe the difference between progressive enhancement and graceful degredation?

Bonus points for the answer “no one can”

Yes, I think I can: “Your frame of reference.” Negative points for assuming the question cannot be answered by anyone. No points off for failing to spell ‘degradation’ correctly.

Jevgenijs Spruzhs Posted: Feb 24, 2012 @ 4:54am

You are a maniac :) . That way you would miss lots of good experienced developers as the most of them do not store all this kind on information in their heads. They will obviously answer SOME of the questions, but not the most of them (except primitive javascript samples of course :) ).
My position is to give really interested developers real tasks in my projects and pay for them (1-2 weeks long period). If they solve them with good quality I would offer a permanent contract.
On the interview I would just check the basics and pay more attention to psychological aspects (how that guy fits my existing team and other personal characteristics).

Chris Sherlock Posted: Feb 24, 2012 @ 6:36am

Dude, the leading font is *awful*!!!! Learn about kerning for goodness sake!

maura Posted: Feb 24, 2012 @ 9:46am

“Can you describe the difference between progressive enhancement and graceful degradation?
Sure. Progressive enhancement is developing to the lowest supported platform and enhancing it by adding the latest/greatest for those that keep their browsers up to date.
Graceful degradation is way more fun for developers, you start out making the best site/app you can and then make sure it degrades gracefully for those using old/inferior browsers.
thanks aneventapart.

R. O. Posted: Feb 24, 2012 @ 9:57am

My favorite ie feature is the close button

[...] Development – Front-end Job Interview Questions “To note, I think that it’s only necessary to choose a handfull of questions from this list [...]

Vlad Patryshev Posted: Feb 24, 2012 @ 1:14pm

“Can you describe the difference between progressive enhancement and graceful degredation?”

English being not my native language, I still suspect that someone who cannot spell “degradation” is a nincompoop; and all their latest-second knowledge is half-nonsense anyway and will be obsolete in a couple of years. The underlying idea seems to be to prove that the interviewer is cooler than whatever competitor comes over to challenge his or her superiority.

Good to know of course; I met a bunch of such idiots-savants during interviews; this one is a remarkable example.

(Carmen Sandiego is in Novato now)

Nick Posted: Feb 24, 2012 @ 9:37pm

“How is JavaScript different from Java?”

If someone asked me this question in an interview I would get up and walk out, because they are obviously idiots.

Jyrki Posted: Feb 25, 2012 @ 6:03am

Q: “What’s your favorite feature of Internet Explorer?”
A: “Help -> About -> Look for any mentions of people who were working to build the piece of shit browser and google their names and find out where they live and fantasize about invoking physical pain to them.”

Chuck Rose Posted: Feb 25, 2012 @ 10:53am

Wow. Based on the tone of most of these comments, I understand why you wrote a post about fear.

Darcy Clarke Posted: Feb 25, 2012 @ 3:58pm

@Chuck Rose appreciate the comment. Yes, this is one of a few good examples where the trolls come out of hiding and decide to criticize instead of contribute. Given the opportunity to change this document on Github I’m extremely surprised at the negative feedback with zero pull requests. If a typo or question arouses such passion you would think people would jump at the chance to change it o_O Weird… Maybe they don’t know what Github is. In which case, they can’t answer questions #2.1.

In any case, here’s the link again for anyone who’s read this far and missed it:
https://github.com/darcyclarke/Front-end-Developer-Interview-Questions

Otherwise, keep trollin’ ;)

Chuck Preslar Posted: Feb 29, 2012 @ 10:09pm

@cancel bubble, i would assume you’re correct:

(function () {
Array.prototype.duplicator = function ( ) {
var duplicated = [];
for(var i = 0; i < this.length; i++) {
duplicated[i] = this[i];
duplicated[i + this.length] = this[i];
}
return duplicated;
}

[1,2,3,4,5].duplicator();
})();

Ivan Posted: Mar 06, 2012 @ 9:34am

As for duplicator I assume he was aiming at:

Array.prototype.duplicate = function() {
return this.concat(this);
};

Thomas Posted: Mar 06, 2012 @ 2:49pm

Thanks for this great list.

I think it’s very valuable, when one just picks the questions which are most important for the job. Someone who can just answer them instantly all like this also probably has already a well paid job.

I have one request:

I would love to see a section with web relevant up to date php questions added.

What do you think of this?

Thomas

ashenkase Posted: Mar 06, 2012 @ 4:04pm

These questions are great if you want to hire a neck beard with zero social skills and a permanent odour issue.

I mirror many others comments here, most competent to excellent front-end developers won’t be able to answer a quarter of these questions in an interview.

I have worked with over a dozen syntaxes in my career, there is no way I can memorize the majority of the information you “think” you want to uncover in an interview from a candidate.

First have a “human” interview were you find out if you want to work with the person. Then test there technical skills via an open book test via Google or by offering the candidate a small project to complete (for compensation).

Michelle Posted: Mar 06, 2012 @ 6:08pm

Glad many people have commented here. I’m very concerned with this because this is being promoted on Smashing magazine as the go-to interview questions list for probably non-front-end developers i.e. managers etc… Who is the interviewer and where are they getting their answers from? In my 12+ years as a ‘Front-End Applicant’ (ugh) I’ve experienced some of these types of interviews where the manager has come in with a list of quickly put together (real world) q & a’s given to them by one of their developers who is possibly introverted and doesn’t want to be in the interview.. and who could feel under pressure to prove the highest level of their knowledge to their manager and not to be undermined by an upstart candidate in the interview. Of course the interviewer doesn’t even understand the questions they are asking so how can that lead to a good outcome? All it says to me is that the hiring staff aren’t clued up and it’s probably not a company I would want to work for.

cenzi Posted: Mar 06, 2012 @ 7:13pm

Darcy, maybe you are wrong from the get go. And this is why SO many people are criticizing you. It’s interesting to want to interview and ask people, so you know, they don’t fuck you over by inventing a false resume… but shit man.. this is wrong. You can’t ask me the ONE question I didn’t know and expect me not to know the other 99%. I’m gonna write a blog post about cars now, even though I’m not a mechanic…

Rosanne Posted: Mar 06, 2012 @ 7:32pm

You’re all coming from the POV of a front-end dev, which is fine, but from the POV of a Digital Ops Manager where I don’t necessarily know much code but I have been doing digital strat since 1995, some of these come in handy.

I’ve interviewed people before whose CVs swore they could do HTML and had buckets of experience but when I asked them point blank in interview what the tag for a table or list was, they couldn’t answer me. I apologise for needing to ask it, because I was aware it sounded condescending, but the right person would have laughed and answered me straight up. The bluffer who is smooth as butter but can’t code to save their lives trips up at that point.

That’s why this list is useful… But Darcy: the answers would be very useful for those of us who *don’t know* the technical details, especially in smaller companies where they might be hiring their first internal dev who will be working with producers and managers but not with any other devs.

Robert Arndt Posted: Mar 06, 2012 @ 9:14pm

Hey, Darcy! I’m a Web Developer/Designer/User Experience/Interaction Design advocate based out of Dallas, TX. Birds of a feather!

But, I simply cannot resist responding to this blog post. I’d strongly encourage you to continue your quest to find web-Jesus, because you very clearly have no glimmer of an idea how to determine whether an individual would be a productive employee!

The first problem, Darcy, is you. YOU are not the type of individual that people would want to work FOR. You are clearly using the interviewing process to quell your own feelings of inadequacy and inflate your own ego. This is really about YOU, Darcy, isn’t it? Your little power trip. I might suggest finding a girlfriend (if you wouldn’t put her through a similar roast). Maybe she could bolster your self-image so you could approach the process of addressing your company’s staffing needs as a mature adult.

I really don’t mean to be nasty, you might be a good guy. But it is really embarrassing that someone in our profession (or any other) would begin the process of establishing a professional relationship with such a charade. What are you seeking to hire, an encyclopedia?

I’ll bet you anything you can’t answer all of those questions, Darcy. Let’s hear your explanation of hoisting without checking Crockford’s book. What is duck-typing? Explain non-greedy repetition in regex objects. How is event bubbling handled in IE4? What languages have you written lints for? See, I can make you feel like a fool, too. How do you like it, Darcy? More importantly, what does it accomplish?

Got a tip for you, Darcy. It’s called Google. That’s right, give me 15 seconds and I can find answers to any of those questions, or any other questions you or your ilk can dream up. I’m not, but I could be the best web-pro in existence and not know the answer to a single one of those questions.

Absolutely NOTHING in all of your interrogation could possible lead you to make a valid determination of who would actually be productive. Apparently you have lost sight of the fact that that is the objective.

If you indeed started your inquisition by asking me if I were on Twitter, I would chuckle and tell you something like “That’s a good one! Good ice breaker!” On Twitter? No, really? Do you actually ask that, or is that a joke? Tell me, how you are edified by a 150 or so character blurb of drivel?

Wanna know about “some examples of repos” that I follow? Following repos? What for? When whatever it is reaches production code status, THEN I’ll make the determination as to whether I can use it to enhance productivity for my employer. By the way, do your employees really have time to “follow” repos, or do you expect them to engage in such scintillating activities on their own time? I thought so.

Oh, don’t forget to ask if they have an iPhone. You’ll also want to know if it’s black or white and what apps they have installed. For heavens sake, don’t neglect to ask about the all-important ring-tones!

Oh, no! The spaces vs. tabs crisis rears its ugly head yet again. There’s a deal-breaker for ya. Sorry, “points off” for you, Darcy! By the way, how many “doctypes” can you name, wise guy? Are there 1, 7, 83 or 1,002,349? From reading this, I’m not sure you even know what a “doctype” is.

I got news for you, bud. You need really good people MUCH MORE than really good people need you! Yeah, applicants are a dime a dozen, but really good, PRODUCTIVE people ain’t! To a really competent, productive professional, employers like you are a dime a dozen. Keep looking.

Mike Taylor Posted: Mar 06, 2012 @ 11:54pm

Robert Arndt, cool story bro.

Tim Branyen Posted: Mar 06, 2012 @ 11:57pm

Just coming here to say that I inflate my own ego with helium and that the girl who appears after a hefty dosage asks me some of these questions. If I don’t get them right I suffer a week of night terrors.

Thank you so much for posting some of the answers. This is really not productive for me, I need all of them.

Gianni Chiappetta Posted: Mar 07, 2012 @ 12:13am

@Tiffany “Hoisting” is not a buzzword, it is a technical term. Learn it.

Gianni Chiappetta Posted: Mar 07, 2012 @ 12:14am

@JR You’re welcome for an awesome list of real-world interview and practice questions (dick).

Gianni Chiappetta Posted: Mar 07, 2012 @ 12:15am

@Ian You’re welcome for an awesome list of real-world interview and practice questions (dick).

Gianni Chiappetta Posted: Mar 07, 2012 @ 12:16am

@Patrick Are you sure it wasn’t because you didn’t know the answers, so instead you decided to whine about it on the internet?

Gianni Chiappetta Posted: Mar 07, 2012 @ 12:16am

@”Why do I want this job again ?” You’re welcome for an awesome list of real-world interview and practice questions (dick).

Gianni Chiappetta Posted: Mar 07, 2012 @ 12:16am

@Steph You’re welcome for an awesome list of real-world interview and practice questions (dickette).

Gianni Chiappetta Posted: Mar 07, 2012 @ 12:17am

@R.B. You’re welcome for an awesome list of real-world interview and practice questions (dick). Study up, buddy.

Gianni Chiappetta Posted: Mar 07, 2012 @ 12:17am

@ashenkase So fucking what if my smartest employee has a neck beard and B.O.? He’d likely code circles around you, and I wouldn’t have to put up with your cocky bullshit. Please go back to copying and pasting your PHP.

Gianni Chiappetta Posted: Mar 07, 2012 @ 12:18am

@Michele You’re welcome for an awesome list of real-world interview and practice questions (dickette).

Gianni Chiappetta Posted: Mar 07, 2012 @ 12:18am

@cenzi You’re welcome for an awesome list of real-world interview and practice questions (dick).

Gianni Chiappetta Posted: Mar 07, 2012 @ 12:18am

@”Robert Arndt” You’re welcome for an awesome list of real-world interview and practice questions (dick).

Darcy Clarke Posted: Mar 07, 2012 @ 12:24am

And so I think this ends our discussion on this amazing blog post which was created and fostered by and for the community. If you have any more concerns feel free to make a pull request.

[...] From: http://darcyclarke.me/development/front-end-job-interview-questions/ [...]

[...] Baseline.  You’ll look good to HR people, and be better able to answer the standard Front End interview questions.  You’ll be good for several years I’m sure.  But me, this stuff is only part of my [...]

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