You Can't JavaScript Under Pressure

[mikeash]

Thanks for immediately playing audio without asking me first. I know everybody just loves it when web pages do that.

[corresation]

Because of your comment, HN will have a dozen "I am so disappointed in all of you" posts in the coming week declaring how mean everyone here is, and how it is no longer like it "once was".

I hope you are happy.

[buckbova]

If using chrome, the Chrome Toolbox has a handy mute all tabs feature. I have it muted by default.

https://code.google.com/p/chrome-toolbox/

[tomscott]

Oh! Hello. This is my thing I made for usvsth3m.com. Hope y'all like it. HTML5 Webworkers made it possible - sandboxing user-submitted JavaScript so an accidental while(1) or document.write can't kill everything.

Do have a look at the source code. Oh, and try turning up your speakers and typing in the Konami code...

[TazeTSchnitzel]

Oh, you, Tom Scott, made it? :D I'm a big fan.

A few suggestions, then:

1. Don't use i as the name of the parameter. A lot of people use that as the name of loop variables, and it means breaking habit or wasting time changing the name.

2. For test 3, try some multiple-extension files to make sure they did it right (some.file.multiple.extensions, should return "extensions")

3. For test 5, it says "integers". Try some non-integers during testing, to make sure that it's only checking for integers.

4. For test 5, it says "arrays". Try some objects to make sure they're not being lazy and using typeof thing === "object"

Anyway, thanks for making this. I love it!

[JosephRedfern]

If you alert() something inside an infinite loop it doesn't seem to be able to detect it (nor does it show an alert box!)

[peeters]

Fun distraction. For me it was:

30% figuring out the answer, 20% not having my editor shortcuts available, 50% figuring out how to check if a value is a certain type.

Am I the only one that gives their functions preconditions that the input is good? To me, throwing up when you're passed a non-number to a sum method is correct behavior.

[dclowd9901]

TIL there is no typeof === 'array'. -_-

[ryanthejuggler]

Could there be a histogram at the end that shows distribution of finishing times? Or at least a leaderboard... I did pretty well [obviously ;)] but I'd like to see where my time falls in relationship to others.

I've confirmed that I can, in fact, code under pressure, but to what degree?

Other than that, fantastically fun game. My only regret is that it's a one-time game by nature, since obviously the second time around you'd simply be remembering what you did the first time instead of creating it.

[Aco-]

A lot of people posted their results to twitter, you can get an idea of where you fall in avg by giving this a glance over:

https://twitter.com/search?q=I%20completed%20%22You%20Can't%...

[cheshire137]

The sudden music/talking that started was annoying and caused me to close the tab immediately.

[brudgers]

No NoScript?

[jenjem]

I took almost 40 minutes, am I in the wrong profession? I figured out how to do all of them right away but I got stuck on figuring out JS syntax in a few places since I barely ever use it and felt like googling was cheating. I did use google on the last one to see how to check if something's an array. I even ended up checking at one point if something's a number by (!isNaN(n/4) && n+n == 2*n), and checked for being a string or not with if(s.length!=undefined) (I know that returns true for an array as well). Would've been a lot easier with something like Intellisense - coding without it feels almost like I'm blind, after being used to it. That and I thought alert() didn't work until I noticed at the end it actually sent it to the output.

[kirse]

Fun little puzzles. First 4 went pretty quickly (~8:00) and then the last one took ~7 minutes Googling around for this so I could test if a variable was an integer...

  n===+n && n===(n|0)

Wish I could see my answers after the fact though!

Edit: Read the initial requirements of the puzzle, it says sum all the integers, not all the numbers. People using (typeof i[x] == 'number') just got lucky because the test-cases didn't exercise the full requirements of the puzzle ;)

  // i will be an array, containing integers and/or arrays like itself.
  // Sum all the integers you find, anywhere in the nest of arrays.

[downtowncanada]

if(typeof i[p] === typeof 3){//it's an int

  sum += i[p];

}else if(typeof i[p] === typeof [3]){//it's an array

  recursion(i[p]);

}

pretty simple no?

[kentor]

    n % 1 == 0

[Justin_Time]

typeof n === 'number'

It didn't actually require differentiating between integers and floats, just numbers and other types.

[chrisrhoden]

n===~~n

[Demiurge]

That was fun! I just got in to work so I was properly sleeping. I also rarely use typeof, so I had to look up that 'integer' and 'array' do not exist :) Also, what was really annoying is the use of 'i' for the argument. That's what I exclusively use for the 'for loop' index! Tripped me up a lot, I had to consciously remind myself every time I accessed the array. Last 'also', the font is WAY too big for my small screen, the comment never fit in, I had to scroll... So I think I did bad, 12 minutes. But still fun :)

[robflynn]

The use of 'i' set me back a bit, too. Caused me to go into an infinite loop at one point.

[Bahamut]

It was a kinda cool thing, although I got some strange behavior when I was using `match` for determining whether the input is a filename - my regex was /.\../ (and so I did var match = i.match(/.\../) ), and match[1] was undefined - turned out match[2] was what I wanted, and it was present, but the behavior was incorrect in the reporting console in the game.

I finished this in 4 minutes.

Edit: looks like HN doesn't like asterisks

[tensafefrogs]

I thought regex was overkill for that one and used:

return input.split(".")[1] || "";

[prezjordan]

Lighten up, everyone, this is a fun little thing. Thanks for sharing.

[ianstallings]

I'm a bit disappointed that it doesn't award points for my heavy use of regex and obscure variable names.

[Cyranix]

> obscure variable names

Absolutely! Being under the gun led me, at one point, to have a "longest string in array" method with a statement like

  if (i[z].length < qq) { ... }

[metaphorm]

there's a truly dubious test case in the File Extension test.

file called .htaccess is not filename "" and extension "htaccess" with a "." separating the two. .htaccess is a unix style dotfile. its whole name is ".htaccess" and it has no file extension.

[taternuts]

I have to admit to cheating and putting 'if (i === '.htaccess') return 'htaccess';' to save time :)

[pak]

It's problems like 5 that make me sad that IE <9 doesn't have Array.prototype.reduce.

    return i.reduce(function(prev, next) {
        if (typeof(next) == "object" && next.length) { return arraySum(next) + prev; }
        if (typeof(next) == "number") { return next + prev; }
        return prev;
    }, 0);

Something that simple needs to be shimmed on earlier IEs. In fact, I had to look up Array.prototype.reduce for this since I usually use Underscore's. Javascript problems...

[1wheel]

https://github.com/kriskowal/es5-shim

[dmak]

Pretty interesting solution. The first thing that came to my head was a loop, but you just used reduce. What are some scenarios where you would use a reduce over a loop? I use underscore a lot too, and I find myself just using _.each all the time

[drdrxp]

The input argument name "i" is really annoying. I always use "i" as for-loop var. Made some mistake on this. But the Game is really great. :D

[dmak]

I got 11 minutes and 14 seconds. Is that slow? The answer to my last solution was like this:

      function arraySum(i) {
	var total = 0
	for(var x=0; x < i.length; x++) {
		if(typeof i[x] == 'object') {
			 arraySum(i[x])
		} else if(typeof i[x] == 'number') {
			total += i[x]
		}
	}
	return total
     }

[lighthazard]

~6 minutes and 30 seconds

That was also my final answer. However, I was going for speed and not elegance, after looking at other people's responses with prototypes and all.

[dclowd9901]

You must've total+= arraySum(i[x]) right? Otherwise this couldn't work as the result of a deep dive wouldn't be utilized anywhere...

[ep103]

you made the same mistake I did at first. Corrected below.

function arraySum(i) { var total = 0 for(var x=0; x < i.length; x++) { if(typeof i[x] == 'object') { total += arraySum(i[x]) } else if(typeof i[x] == 'number') { total += i[x] } } return total }

[peregrine]

Total bait and switch. As soon as I saw that random array in my array of strings I knew what kind of game this would be.

[hcarvalhoalves]

Last one reminded me how awful JS is once again. There are 5 different ways to check if an object is an array, some are implementation dependent, and the obvious one doesn't work (typeof x == "array").

[hayksaakian]

typeof(x) === typeof(["something which is certainly", "an array"])

or am i missing something?

[Bahamut]

x instanceof Array

[salehenrahman]

I created a CoffeeScript version of it. http://shovon.github.io/youcantcoffeescriptunderpressure/

[axyjo]

"6 minutes, 21 seconds for all 5 levels. Well done!" I feel like I should have done better considering JS is one of my primary languages.

[jamesroseman]

9:10, had to Google a bit for type checking, and I had forgotten the proper syntax for a string split. :-/

[salehenrahman]

I got 3 minutes 39 seconds.

I used i.forEach for questions involving arrays, instead of for-loops. Saves me time.

[leehro]

This was awesome. 5:48. I actually turned my sound on for the end.

[chudi]

nice stuff but this is plain wrong! // return the file extension (with no period) if it has one, otherwise false

its like returning error codes in C for errors

[jamesroseman]

I too shuddered at this instruction...

[ep103]

What's everyone's times? I did 7 minutes

[oftenwrong]

8:30

Spent nearly the entire time on #3 because I was trying to use String.replace to work and failing. Ended up using .split instead, which passed thanks to poor test coverage (just like at work!).

[EdgarVerona]

8:11 for me - as it sounds like was the case with others, the majority of that time was searching for how to check for specific types in Javascript.

For the "is this actually a string?" check, for example, I started looking for the existence of the match method on the object, which of course would have failed if they passed some random object with match defined so I cheated a bit. I'd like to see the full breadth of test options people took out there.

[methodover]

14 minutes, 27 seconds for all 5 levels. Bah, should've done better. On the other hand I just woke up.

I wanna see one of these in Python.

[hatsuseno]

My JS is somewhat rusty, glad I had a .map() to work with. 9 minutes something, I did 'cheat' by looking up some typeof returns.

[dpedu]

6:11.

Blew through the first 4 but spent half my time on the last one because I don't have Javascript type checking memorized.

[robflynn]

"2 minutes, 32 seconds for all 5 levels. Well done!"

The "kill screen" song is stuck in my head now.

[nakovet]

I only did one time: 8 minutes and 57 seconds, for sure the next try will be way easier.

[myh]

5 minutes, 31 seconds for all 5 levels. Well done!

[Justin_Time]

4 minutes, 56 seconds for all 5 levels. Well done!

[dmak]

11 minutes 14 seconds. I wish I did faster!

[CompelTechnic]

17 minutes, 47 seconds. slow poke here.

[mneary]

Just under 3 minutes!

[Demiurge]

12:45

[renekooi]

2:26.

[trevordixon]

4:20.

[ryanthejuggler]

3:15

[Kiro]

Would be great to see some solutions.