Return True to Win

http://alf.nu/ReturnTrue

by moklick • 10 years ago

234 116 10 years ago

alf.nu

Zekio2• 10 years ago

I quite like this kind of challenge :)

lalala1995• 10 years ago

Please more levels

idbehold4• 10 years ago

You've already finished wat, undef, random3, and random4?

fennecfoxen2• 10 years ago

wat, undef

Oh, undef is as easy as knowing HTML trivia. Getting a falsey value to return an arbitrary string when invoked as a function is at least a little harder...

random3

... is almost as easy as random1

random4

is exactly as impossible as it looks

dou4cc• 10 years ago

The game shows us how ugly JS is.

tomelders2• 10 years ago

Swift. The Javascript of tomorrow, today!

k_bx• 10 years ago

PureScript. The Swift of today. Yesterday, today and tomorrow!

posterboy5• 10 years ago

Indeed, I refuse to believe there should be a solution to the 'reflexive' task.

teraflop• 10 years ago

That one isn't specific to Javascript, though. If you can find a mainstream language that doesn't have any values that aren't equal to themselves, I'll give you a cookie.

(Going from memory of the last time I tried this challenge, since I can't get it to load at the moment.)

XaspR8d• 10 years ago

So you disagree with the IEEE floating point specification, then? Javascript is directly following spec there.

plank2• 10 years ago

Took me a couple of tries... (Spoiler): Anyone anything shorter then 4 characters (two characters)?

plank2• 10 years ago

Ah. 2 distinct characters now.

lma21• 10 years ago

How did you solve the reflexive? I'm not getting at anything :(

Zekio2• 10 years ago

I broke things to do it

[] - {}

TobbenTM• 10 years ago

Yeah, tricky one. NaN works though. Because NaN == NaN = false

Burgos• 10 years ago

`NaN`

kqr2• 10 years ago

NaN != NaN. It's how you're supposed to test for NaN, apparently.

kitfung• 10 years ago

reflexive( function() {return ++window.x;}() )

razorsese• 10 years ago

Infinity - Infinity

weisk• 10 years ago

Another version, also 3 characters: 0/0

bradleydwyer• 10 years ago

Yup. !0

0x4139• 10 years ago

!0 - 2 chars 1>0 - 3 chars

justinlardinois2• 10 years ago

I used !!1

nxzero• 10 years ago

Reminds me of "The Little Lisper" and coding koans; honestly thought it'd be harder to "win" the challenge.

xyclos• 10 years ago

This is a nice challenge to start the morning.

However, on mobile the input loses focus after each individual character typed which is quite frustrating.

grabcocque• 10 years ago

'Break JS to win!'

idbehold4• 10 years ago

Let me document all the reasons I dislike the HTML spec: it defines a willful violation of the ECMAScript standard.

xeniak• 10 years ago

Can you elaborate?

idbehold4• 10 years ago

Well, it's kind of a hint for solving some of the more "that's impossible" problems on here. I don't want to give the whole thing away.

fennecfoxen2• 10 years ago

I'll use a link shortener to prevent spoilers. This link elaborates exactly which rules are abused: https://goo.gl/mu5xtr

"These requirements are a willful violation of the JavaScript specification current at the time of writing. The JavaScript specification requires that ToBoolean return true for all objects, and does not have provisions for objects acting as if they were undefined for the purposes of certain operators. This violation is motivated by a desire for compatibility..." with old Internet Explorer.

fauria• 10 years ago

This table is quite useful to solve some problems: https://dorey.github.io/JavaScript-Equality-Table/

liquidise• 10 years ago

Moral of the story: Always use 3 equals unless you have a good reason to use 2.

  NaN === Nan  // => false
  [] === []    // => false
  {} === {}    // => false
  [1] === [1]  // => false
  [0] === [0]  // => false

I guess i never see the gains in the triple vs double equal sign wars.

idbehold4• 10 years ago

Do any of those return true if you use double equals? The distinction only really comes up when you have to different types on either side and then It will coerce one of the types to match the other.

TAForObvReasons2• 10 years ago

None of those are true when using `==` either.

The NaN example comes directly from IEEE754

The others are based on the fact that the two sides are not referring to the same object. C "equivalents" of your examples:

    int x[0], y[0]; x == y; // false
    typedef struct {} empty_t; empty_t *x, *y; x == y; // false
    int x[] = { 1 }, y[] = { 1 }; x == y; // false
    int x[] = { 0 }, y[] = { 0 }; x == y; // false

jomamaxx4• 10 years ago

Those non equations are perfectly reasonable.

One array or object does not equal another, different one.

There are definitely gains - I strongly suggest following the 'moral' of the story.

At least the === paradigm is fairly consistent and mostly rational.

imtringued• 10 years ago

You're comparing two expressions of the same type so it doesn't matter whether you use == or ===, but == can return true even if the expressions are of different types.

AgentME2• 10 years ago

[] and {} create new objects. === always compares by identity, which isn't a unique feature. It's equivalent to Java's ==, and two different objects aren't ever equal to each other. === is equivalent to Python's `is`, and you'll get false from `[] is []` in Python for example.

pselbert• 10 years ago

This notion of equality would make pattern matching on empty lists or objects impossible in languages such as Erlang or Haskell. Perhaps it makes sense with the knowledge that each array is a different object, but it is highly counterintuitive.

Kapow• 10 years ago

JS gets even weirder when you include all the comparison operators.

https://jsfiddle.net/5Yzs6/17/

Did you know undefined is equal to undefined, but not <= undefined or >= undefined?

Or that two instances of the same object/array are not equal (e.g. [-1] != [-1]), but are both <= and >= each other?

Or that /.*/ is non-comparable (only != is true) to all numbers, but greater than [-0.5] and "-0.5", and less than [0] and "0"?

andrepd• 10 years ago

What a clusterfuck.

AgentME2• 10 years ago

Most of the examples you point out make sense if you know that using greater than or less than casts the value to a number. >= and <= always cast their parameters to numbers while == only does if either side is already a number.

alexmorenodev• 10 years ago

What the hell am I reading.

stoic• 10 years ago

With games like these I feel like we all lose

jomamaxx4• 10 years ago

This is true.

Pun intended!

Tepix• 10 years ago

It doesn't seem to work for me on Firefox and Chrome..?

kakarot• 10 years ago

It wasn't working on either for me, so I came here to complain, went back and it was suddenly working. Dunno what the issue was but keep trying maybe

vog• 10 years ago

Yes, it seems to take quite a while to start up.

Spoom• 10 years ago

I had to go into the console and type "return true" for it to start working. I thought it was intentional.

mk7• 10 years ago

I am so unhappy, because I can not play such games with Java... ;-)

ninjakeyboard2• 10 years ago

I don't exactly know what I did, but it did say that I win.

junke• 10 years ago

A day like any other with Javascript ;-)

noobermin• 10 years ago

s/with Javascript/being alive/

okket• 10 years ago

This page only shows "return true to win" on a white background in Chrome?

moklick• 10 years ago

seems to be down :/

tomsmeding• 10 years ago

It loads eventually

scrollaway• 10 years ago

Does it?

ReturnTrue:1 Fetch API cannot load https://bigger.alf.nu/db/true/H5VmsyVCBD62113H5Slu. No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'http://alf.nu' is therefore not allowed access. If an opaque response serves your needs, set the request's mode to 'no-cors' to fetch the resource with CORS disabled.

qwertyuiop9242• 10 years ago

I already saw this on lobste.rs, but it's still cool. I like ES just fine, but to think we could have had scheme instead. Gee, thanks Netscape:

Every time you win, everybody loses.

ninjakeyboard2• 10 years ago

"it's because of you, motherfucker, that we're not all using lisp" @ 5:00 https://www.youtube.com/watch?v=bzkRVzciAZg

qwertyuiop9242• 10 years ago

No, that's actually the fault of Netscape.

Anyways, that video is awful and totally wrong. Node code can be clean, threaded code can be ugly. Both can be fast, but the perf characteristics are different (for OS threads, anyways).

apricot• 10 years ago

Find the exact combination of browser/OS that does more than show "return true to win" on a white background to win.

throwanem3• 10 years ago

Use patience.

wtbob• 10 years ago

Find the exact combination of browser/OS that does more than show "return true to win" on a white background to win.

I see:

    return true to win
    
    (Come back in a few minutes.)

What do I win?

throwanem3• 10 years ago

A moment in which to reflect.

dingo_bat• 10 years ago

I got 'Sorry for the delay.'

mtrycz• 10 years ago

meeeeeta.

sirsuki• 10 years ago

TypeError: NetworkError when attempting to fetch resource.

Maybe the challenge is to fix HTTP?

nfriedly• 10 years ago

It loaded for me eventually. First one is pretty straightforward. After that they seem to require knowledge of JavaScript quirks.

unsignedqword• 10 years ago

Does anybody really know why JS's type system was designed the way it was? It seems so out of whack with what people want out of a language, dynamically typed or otherwise.

throwanem3• 10 years ago

It wasn't; the language was implemented from scratch in ten days.

mherrmann• 10 years ago

That explains a lot. Source for others that are interested: https://www.w3.org/community/webed/wiki/A_Short_History_of_J...

bhrgunatha• 10 years ago

Obligatory - https://www.destroyallsoftware.com/talks/wat

curveship3• 10 years ago

It's because Eich was told to make JS C-like. In C, an empty array, an empty string, 0, false and null are all the same value: a word with all bits 0. So in JS, those are all are falsy and == to each other.

jomamaxx4• 10 years ago

I wish an empty string was not false.

In 'object' terms, an empty string is still a string! It's something.

I guess if you think about it from a memory perspective, it's 'nothing'.

But since JS is not actually like C, I really wish "" were true.

Triave• 10 years ago

In C, empty strings are truthy, being a non-null pointer to a NUL character. Depending on what you mean by "an empty array" that might also be a non-null pointer to a zero-length region of memory, and thus also truthy in C.

sladix2• 10 years ago

Does someone have a <52 char solution for the counter one ?

nikital• 10 years ago

One solution:

    function(c=1){return function(){return c++}}

44 characters

curveship3• 10 years ago

(x=0)=>()=>++x

sladix2• 10 years ago

Holy crap, that's what I call refactoring !

posterboy5• 10 years ago

that's ascii art, not code

awalGarg• 10 years ago

You can save one character by doing this:

(x=0)=>_=>++x

the underscore is another variable but a single variable does not require parenthesis. So instead of two chars for the two parens, you use a single char for a single letter variable. JS FTW ;)

Bahamut• 10 years ago

  i=>_=>i=-~i

curveship3• 10 years ago

For the first 5, I've got 2,3,8,14,7. Anybody got tighter solutions?

esnard• 10 years ago

I got 7 on the third challenge with that solution:

    transitive([],0,[])

plopilop• 10 years ago

The counter one (level 4) can be done with 11 chars. Solution below, found on Reddit[1]. Also, I could not manage fewer than 9 characters for level 3. (Edit: thanks @ensard)

Spoiler here: x=>_=>x=-~x

And also in this link: [1]: https://www.reddit.com/r/programming/comments/4wd32v/return_...

brudgers• 10 years ago

Fri Aug 12 14:35:18 UTC 2016:

Page had message that the Hacker News 'hug' was likely to affect performance.

conkrete• 10 years ago

▶ id(true ) // (4 chars)

▷ true

You win!

agentgt2• 10 years ago

What is with the User/Score/Browser table? I only did like 4 of the tests and that thing popped up. I would finish it but I have some other things to do.

danielweber• 10 years ago

I can't get past the first test.

Pfhreak• 10 years ago

Looks like once you successfully score, it shows you how many characters it took others to solve. For example, the first one you can trivially type in true to solve it, with four characters. But it's solvable with only two characters.

agentgt2• 10 years ago

Yes but there is no where you can enter your screen name. I should have clarified that in my question because I got down voted for asking this.

The whole down voting thing imo really has to go. Just flag answers or up vote. The whole bro intellectual rudeness is sort of off putting.

CGamesPlay• 10 years ago

My gosh, this is way harder than the alert(1) series. http://escape.alf.nu

billpg• 10 years ago

I typed "true", without the quotes.

Did I do it wrong?

marxidad• 10 years ago

It's code golf. Try to do it in less than 4 characters.

nightpool• 10 years ago

There are more levels

omaranto2• 10 years ago

The link points to a page that only contains the text "return true to win" in large type on a white background. As with most modern art, I don't get it.

justinlardinois2• 10 years ago

Are you browsing with Javascript disabled?

omaranto2• 10 years ago

No.

Return True to Win

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