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JavaScript Is Weird

jsisweird.com

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Re: JavaScript Is Weird

#311

Post by holtalanm »

some_random wrote: post #220
holtalanm wrote: post #210

Earlier quoted context omitted.

> Calling these things weird is fair enough but I can't help thinking this is code you'd never actually write outside of the context of a "Look how weird JS is!" post. That is the whole premise of the site, though. They even say that these examples aren't common syntax or patterns before you start.

The site is called "JavaScript Is Weird", not "Weird Javascript", even if they tell you that the examples aren't common they're still saying that this weirdness is unique to JS. Which definitely isn't true in the case of basic floating point precision problems

> The site is called "JavaScript Is Weird", not "Weird Javascript"

am i being punkd?

Re: JavaScript Is Weird

#312

Post by JoshuaDavid »

otabdeveloper4 wrote: post #309
Tainnor wrote: post #257

Earlier quoted context omitted.

I've been thinking for a while that modern languages shouldn't default to floating point computations. They're exactly the right thing if you do data stuff or scientific computing, but given how much of the internet relies on things like e-commerce and how often floating point is still misused for dealing with money, coupled with the fact that even many senior developers aren't fully aware of the subtleties of floati…

Having the full number stack supported (natural numbers - integers - rationals - reals) would be, indeed, awesome. Sadly, most people don't understand the distinctions, so this will never happen. (Even in reply to your post people keep talking about "decimals", as if the number base is at all relevant here.)

"Decimal" usually refers to a data type which is "integer, shifted by a known number of decimal places". So, for example, if you had an amount of money $123.45, you could represent that as a 32-bit floating point number with (sign=0 (positive), exponent=133, mantissa=7792230) which is 123.4499969482421875, but you would probably be better off representing it with a decimal type which represents the number as (integer part=12345, shift=2), or as just a straight integer number of cents.

The number base is relevant, because money is discrete, and measured in units of exactly 1/10^n, and if you try to use floating point numbers to represent that you will cause your future self a world of pain.

Re: JavaScript Is Weird

#313

Post by wwosik »

qayxc wrote: post #133
vvoyer wrote: post #97

I stopped at the first example (true + false). If you write code like this, you have bigger problems than using JavaScript. For most of the examples, it's like saying "Here's what happens when you plug a fan to a faucet". There's no point really. JavaScript is weird just like any other language can be weird when you use it in weird ways. And yes, it's certainly one of the weirdest. If you want to talk about things we…

> I stopped at the first example (true + false). So you never did something like this: x = performCalculation(getParam1()) y = performCalculation(getParam2()) sum = x + y only to discover that "performCalculation()" sometimes returns a boolean instead of a number? JS is a dynamically typed language after all and functions like function f(x) { if (x >= 0) { return Math.sqrt(x) } else { return false } } are perfectly v…

Typescript to the rescue ;)

Re: JavaScript Is Weird

#314

Post by blacktriangle »

applecrazy wrote: post #283
_nub3 wrote: post #233

Earlier quoted context omitted.

TypeScript wont magically fix type errors. It is not that hard, to sanitize any expected parameter for functions and their output, typescript wont do that for you. So if you typecheck i/o values per se, using typescript only slows down dev process, as this can be easily done in vanilla javascript. no need for more bloat, but only for some defensive programming.

> no need for more bloat What bloat are you referring to? TS compiles down to plain JS.

Toolchain bloat is still bloat.

Re: JavaScript Is Weird

#315

Post by jiofih »

hootbootscoot wrote: post #223
jiofih wrote: post #75

Earlier quoted context omitted.

That’s a load of gibberish. JS as a language has nothing to do with browser APIs, why would you judge it based on that? Also, ES6 was ratified six years ago. Seems like you had a bad experience with espruino / jerryscript or something and are projecting based on that? Dynamic languages are easier to program in. That’s a fact, and why they are so popular.

gibberish? "JS as a language has nothing to do with browser APIs, why would you judge it based on that?" Excuse me? That is precisely what JS is based upon. Lemme give you a prime example: JS = a single threaded event loop, ON PURPOSE. That directly affected Node.js as an implementation. Your browser has an embedded scripting engine. Embedded, meaning, the source code for your browser includes the scripting language…

> That directly affected Node.js as an implementation.

It didn’t “affect” node, it was the whole reason it came to exist: its cooperative multitasking was a good way to tackle concurrency (remember c10k), and V8 was available and easily embeddable. Without the event loop there would have been no reason to choose JS.

Re: JavaScript Is Weird

#316

Post by akiselev »

Tainnor wrote: post #302
denton-scratch wrote: post #290

Earlier quoted context omitted.

> "# use-floating-point" pragma I haven't come across the "pragma" directive in a Javascript context. I guess it's another new feature (I have trouble keeping up these days).

I don't think they have it (although, you can do whatever you want with babel nowadays, I guess). It was a suggestion aimed at programming languages in general.

The javascript equivalent would be an expression like 'use strict';

Re: JavaScript Is Weird

#317

Post by akiselev »

lostcolony wrote: post #269
dangerbird2 wrote: post #222

Earlier quoted context omitted.

If the good lord wanted us to code in assembly language, he'd have made transistors operate on mnemonics, not electric currents.

If the good lord had wanted us to interact with transistors based on mnemonics, not electrical currents, he'd have implemented our brains in mnemonics, not electrical currents.

Nitpick: voltage potentials and ion channels. There's not much actual current flowing.

Re: JavaScript Is Weird

#318

Post by an1sotropy »

Demiurge wrote: post #237

I love that 1/0 = infinity in JS. It's as pragmatic as a tired student doing their algebra homework at 1AM :))

Like others have already noted; 1/0 == inf is something about JS, it is a consequence of JS defaulting to IEEE754 floating point representation for all numbers. Any language that supports IEEE754 FP will have the same result.

Re: JavaScript Is Weird

#319

Post by ufmace »

foepys wrote: post #59
blowski wrote: post #30

Earlier quoted context omitted.

Exactly. Finding flaws in a language doesn't mean the language is bad, just that it has... flaws. The proof that JS is actually pretty good is that it has been used to build so many things. Like the old adage about economics, these criticisms are taking something that works in practice and trying to see if it works in theory.

Just because something is popular isn't reason for it to be good. Examples: fossil fuels, (over)fishing, rage-based engagement, hard drugs.

Uh Fossil Fuels powered the Industrial Revolution and literally created the modern economy.

It's true that being popular doesn't necessarily make something good. But it's also true that having some flaws discovered later doesn't make something that revolutionized the world and massively uplifted the standard of living of basically everyone in it bad.

Re: JavaScript Is Weird

#320

Post by Hermitian909 »

denton-scratch wrote: post #294
ozim wrote: post #244

Earlier quoted context omitted.

Can it be that JS is not good starting language then? Maybe strongly typed compiled languages would be a better fit? One can argue that if you want to program it might be too much information for starters - but IMO basic types are such a fundamental concept that it would be better to teach that concept early on. It also clears up a lot of newbie confusion as you cannot assign string to an int by mistake with strongly…

> Can it be that JS is not good starting language then? @ozim, I don't believe you are trolling! JS is an absolutely awful language for beginners; it's a 155mm howitzer pointed at your foot. Although you can get the hang of the basics quickly, AND it runs in the browser (super-convenient unless you're headless), those "basics" that you thought you'd got the hang of turn out to have semantics that make sense, but are…

Having designed programming curriculum, I have to disagree that the language is a bad language for beginners (though it is very far from ideal).

To be fair the primary reason is not really a virtue of Javascript per se, but the fact that it runs in the browser is a large pedagogical gain that no other language can easily match and is hard to overstate. Learning to program is overwhelming for most students, and setting up your environment is a major component of that. Being able to run your code natively in the browser is a huge boon. Even better, having that code immediately be useable in a very real sense boosts motivation significantly. For most students it really is preferable to let students get very comfortable with basic code constructs before having to interact with the underlying system in any meaningful way.

At the language level, Javascript also has some nice affordances that let you treat constructs as simpler than they are in your curriculum and expand on them later. I think the best example of this is `var`. Viewing variables as uncomplicated "buckets" that happily contain any data you want to shove in them is a good starting place when introducing the very first building blocks of something like if/else control flow.

Most languages are built with semi-experienced programmers in mind and are ill-suited for many beginners and actively bad for children. As an easy example: as a developer I like seeing type specifications for numbers, but pedagogically having to introduce the difference between ints and floats on the first day is just empirically confusing for most students. Much better for them to be "magic" until you can properly motivate them to care (which can be just a few weeks in!)

I could write on this topic far longer than I have, but the short of it is that Javascript has done a truly surprising number of things right for a teaching language. I'd still love to remove some of the zany examples here if I could though.

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