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Return True to Win

alf.nu

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Re: Return True to Win

#91

Post by andrepd »

Kapow wrote: post #82
fauria wrote: post #21

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

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 that two instances of the same object/array are not equal (e.g. [-1] != [-1]), but are both = 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"?

What a clusterfuck.

Re: Return True to Win

#93

Post by astrobe_ »

XaspR8d wrote: post #80
posterboy wrote: post #58

Earlier quoted context omitted.

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

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

Does that spec forces you to implement equality test between floating point numbers?

Re: Return True to Win

#94

Post by nv-vn »

jomamaxx wrote: post #84
curveship wrote: post #77

Earlier quoted context omitted.

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.

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.

"" is actually true in C, but that's also because it represents something in memory. Consider how C encodes strings: an empty string is a _pointer_ to a 0 (or a '\0', if you want to think of it as a char). However, the pointer (being an address) is non-zero (since the address 0 is NULL).

Re: Return True to Win

#96

Post by Etzos »

posterboy wrote: post #87
teraflop wrote: post #74

Earlier quoted context omitted.

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.)

The important property of evaluation is determinism defined by the equality of the output. Classically, id(x) != id(x) is logically inconsistent. Boolean Logic and natural languages are pretty mainstream in my opinion. Do you mean programming languages? If IEEE whatsthenumber is implemented in the FPUs to provide fcmp (Floating-point Compare Instruction), the languages don't have much of a choice. When there are diff…

You seem to be splitting hairs and I'm not entirely sure why. Following the flow of conversation it should be pretty easy to infer the parent was referring to programming languages. Originally you said you don't think there should be a solution to the reflexive problem, and that in reply to a comment mentioning that Javascript was ugly (which is where the context of _programming_ language came from). I, and I believe the parent as well, took that to mean that you consider Javascript ugly because you don't believe it should operate the way it does. However, the point the parent was trying to make is that this is something common to all (programming) languages which follow the IEEE 754 standard and is therefore not some special case which makes Javascript any more ugly than another (programming) language.

It may not seem obvious and it may seem logically inconsistent but, like you said, this is computer science and things don't always work exactly the way we think they should. Usually because the obvious logical solution has problems when implemented so we change things around. In this case, NaN != NaN because of some of the limitations at the time IEEE 754 was proposed.

Re: Return True to Win

#98

Post by Pfhreak »

agentgt wrote: post #89

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.

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.
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