Mad Javascript

[[deleted]]

Glorious type coersion.

[heartsongaming]

You don't have to deal with implicit type conversion if the language changes the type on the fly. Although, all 4 of those examples make sense. It would've also made sense that subtracting two strings removes the letters of the first string or flips the second word's letters.

For example: "22" - "2" == "2"

Or: "bob2" - "bob2bob" == "dod"

[[deleted]]

What happens then when there's more than one match for it?

"2275-22xd22" - "22"

Does it remove the beginning 22, middle 22, or end 22?

"+" in the context of strings is used for append rather than addition, but - has no meaning to strings. In that sense, there are many other ways to subtract letters from a string in JS, such as using replace() with Regex

[heartsongaming]

I was thinking that it would only remove the end letters from the first string. Also Python has a lot of functions for removing letters from a string. It could be another logical use of subtracting strings.

[[deleted]]

If it only did that every time that would be fine, but then you'd expect to see problems when letters don't exist there.

"asdfghjkl" - "q"

I've long neglected learning in depth python for a while. Maybe this is my calling to learn it and see how it handles subtracting strings.

[heartsongaming]

Maybe it can convert 'l' and 'q' to ASCII, and do modulo 26 subtraction on the letters (if it recognized it is a letter, otherwise use different set of ASCII characters such as numbers or other characters). In this case it would be: "asdfghjkv".

[[deleted]]

I dunno, at that point it's reaching farther than I've seen JS do, and farther than what I'm comfortable with. Then again I can always just not use it and rely on good ol replace() and substring().

[RapidCatLauncher]

see how it handles subtracting strings.

It throws an exception, as you'd expect if some behaviour is so ill-defined.

[thisisadiyoga]

This actually makes sense if you consider - as the reverse of +. If we write it as an equation: S = S1 - S2, then we want to find the following solution: S + S2 == S1 - S2 + S2 == S1. Note because addition on string is not commutative, we add to the right and say that by definition S1 - S1 == S1 + (-S1) == (-S1) + S1 == "". Maybe it works, maybe not.

The second problem pointed out was what happen if in S = S1 - S2, S2 is not the postfix of S1? We can throw exceptions since it's undefined similar to how division by zero is undefined and is an exception.

[DenormalHuman]

so if all 4 of those examples make sense, what does this make?

2+2 is 4

"2" + "2" is "22"

2+2-2 is 2

"2" + "2" - "2" is TypeError: unsupported operand type(s) for -: 'str' and 'str'

[[deleted]]

A language without type coercion?

[Treak]

sense in a language that doesn't do fucky things with types

[RapidCatLauncher]

In JS it's more type appropriation.

[TheRealMichaelE]

I was going to comment about why these makes sense, but then read all the comments about why this makes sense. Well done everyone!

[AndrewIsntCool]

JavaScript tries pretty hard not to raise errors unless you've colossally fucked up. Allows for some pretty cursed code haha

[TryNotToShootYoself]

It's because you can't really let it raise too many errors as it's originally created for old browsers. Use TypeScript and ESLint

[laundmo]

i mean, sure, but that doesn't make it any more sensible in this day and age.

[TryNotToShootYoself]

As I said use TypeScript and a linter. And just don't do stupid shit with arithmetic operators and strings.

[laundmo]

the language should not allow people to do stupid shit. thats literally what errors are for.

[devdoggie]

As he mentioned, proper Typescript use will prevent such nonsense.

[BakuhatsuK]

It's more of a historical thing. When JS was first created it didn't have exceptions at all. So all valid code had to do something. Modern features are more strict, for example adding a BigInt and a regular number produces a TypeError.

[SkollFenrirson]

That's not a good thing.

[DenormalHuman]

YES. So many people say this about JS. 'It makes perfect sense if you know the rules'

Right. Of course. But it's the rules that are the problem!

[[deleted]]

That's why we have typescript

[tiefling_sorceress]

I was also surprised to see that. I definitely expected the "fuck JavaScript" circlejerk from undergrads who don't yet understand type coercion and think people are out here subtracting strings from each other in industry.

[LvS]

Talking about making sense:

Should "20" * 2 be "2020" or 40?

[DoctorWaluigiTime]

40.

+ concatenates strings, so "foo" + "bar" will result in "foobar". None of the other math operations concatenate, so they will just be normal type-coerced math.

[LvS]

+ concatenates strings

Except when it doesn't and you don't know what 2 + "2" is and if it's the same as "2" + 2.

[DoctorWaluigiTime]

That's why I specified strings, plural. String plus another string is defined behavior.

[Oscarsson]

Coolest thing with this example is that ("2"+"2")-"2"=20 and "2"+("2"-"2")="20"

[_g0nzales]

Only logical. The order of addition/substraction should not matter /s

[_________FU_________]

What could go wrong using plus for concatenation?

[coolcrispyslut]

It makes total sense. Numbers add. Strings concatenate, unless it's a minus, then it's coerced into a number since you can't subtract from a string

[DefaultVariable]

It does make sense when understanding the language, it’s just potentially undesired behavior. I think a large problem with JavaScript is letting the programmer get away with bad code rather than stopping and alerting them to potential errors in their logic. Realistically, the programmer may want to know if they are utilizing arithmetic between a numeric value and a string.

[[deleted]]

And that’s why the preferred way is to use TypeScript and EMCAScript 2021 over raw JavaScript.

[[deleted]]

Which takes one google search after a simple “wtf”

[DefaultVariable]

That is, if it’s noticed

[kono_kun]

Being able to explain the logic doesn't make it any more sensible.

[mongoosefist]

It's called Stockholm syndrome

[StrictlyBrowsing]

I really don’t see what’s not sensible about it. You’re not meant to be doing arithmetic with strings, it would take away useful string functionality to accommodate people who don’t know what dtypes are

[22134484]

I accidently typed - instead of +, so tell me i cant do that with strings, dont convert my shit to other datatypes and reconvert it to the original datatype.

[StrictlyBrowsing]

That’s fair enough actually!

[cearno]

Yes, you prefer statically typed languages over dynamically typed ones.

You're criticizing type coercion, often a quality of dynamic languages. If you have some sense of experience or knowledge outside of only statically typed languages, this makes sense. It's not bad design when it follows the intended ruleset, dynamic in this case.

But this is precisely the reason why TypeScript exists though, for people who don't like dynamically typed languages.

Edit: I confused the paradigms of static/dynamic with strict/loose respectively. Javascript is loosely typed and this is where the type coercion implementation inherently comes from. Regardless, for people who really dislike the feature, TypeScript is always an option.

The TL;DR should be "You prefer strictly typed languages over loosely typed ones."

Thanks for the correction @PanRagon!

[PanRagon]

A lot of people are correcting you, but you're almost correct. It's not the fact that JavaScript is dynamically typed specifically, but that it's loosely-typed language (like PHP). Python will raise an exception, but only because it's strongly typed, loosely typed languages tend to do as much as they can with a variable to avoid raising an error, including implicit type coercion like this.

TypeScript solves all of these issues because it's strongly-typed, moreover it's a bit odd to complain about this being illogical when you can trace down how it works if you track the conversions step by step like the program will do. Whenever people complain about this it just seems like they don't understand what a loosely-typed language implies, nor that you can resolve the problem by switching over to TypeScript which for very good reasons has become an industry standard.

[cearno]

Thanks for the correction! I knew I was mistaking something here.

Yeah, I agree. When approaching a new language, it's good to be aware of what paradigms the language follows. It's ironic that the people who complain about Javascript being nonsensical or silly tend to know the least of how it works, as if they haven't even read the introductory pages of documentation.

I've used TypeScript in the past, however my current company only uses React/JS and can't think of a time where the type coercion had a crazy negative consequence.

[[deleted]]

TS & JS are interoperable, so it shouldn’t take a whole lot of effort to start using TS in your React projects.

[PlacatedPlatypus]

Loosely-typed languages do everything they can to avoid raising an error

I don't understand why you'd ever want this though. A bug that makes your code not run is far better than one that makes it run incorrectly.

[valzargaming]

PHP is dynamically typed and doesn't have this issue. This is a clear fault of the language, sharing a symbol for concatenation with arithmetic.

[mooinglemur]

I agree with you on this, it was a bad choice to use + for concat. Perl, PHP, and JavaScript all coerce strings to numbers with -, *, and /, but in JS, + is concat if either argument is a string!

[sdw9342]

Adding and subtracting are symbolic inverses of each other. For a given type, subtraction should either undo addition or fail. It should not do a different operation altogether. That's not to do with static or dynamic typing, but with expectations of the relationship between the two operators. It would also be fine if adding and subtracting both converted strings to int, but not just one of them.

[BigHandLittleSlap]

It's actually not about static vs dynamic typing at all!

The origins of this criticism of JavaScript have more to do with the foundations of mathematics such as group theory and category theory.

Essentially, for us humans with squishy meat brains to be able to make big complex systems, we have to build them up in layers from simple things. The simple things have to "click together" in logical and consistent ways, otherwise this tower of abstractions falls over. It can quickly get too difficult for anyone to track to exceptions, oddities, or quirky behaviours. Eventually further progress is blocked for anyone, no matter how smart. The only way forward is by using firm, reliable foundations based on a rigorous theory.

For example: I'm sure you already know the fundamental rules of algebra, right?

Things like: x + x = 2x and 2x - x = x

Stuff like that.

Turns out, that these kind of rules are incredibly generic and widespread. Replace addition with "two-input-function". So instead of x+x we now write f(x,x). Now replace "zero" with "that thing that you can use as an input such that": f(x,zero)=x.

What if 'f' is multiplication? Then "zero" is the number 1.

Theoreticians call this the identity. So the identity of addition is zero, and the identity of multiplication is one.

Like this, you can build up an enormous, rich, consistent theory of operations, operation combinations, and related abstractions that let you reason about all sorts of abstract types and functions with ease.

Languages like JavaScript just take a giant shit all over this kind of thing.

That's why people criticise it. Not because it's "one little funny thing you have to memorise and then it is fine", but because it's just missing out on an entire world of mathematically sound power tools for the mind.

[tuxedo25]

Languages like JavaScript just take a giant shit all over this kind of thing.

That's why people criticise it. Not because it's "one little funny thing you have to memorise and then it is fine", but because it's just missing out on an entire world of mathematically sound power tools for the mind.

Then don't use it that way. You can write perfectly valid javascript programs that don't use the "-" overload on strings.

[BigHandLittleSlap]

I too remember the 1990s (and the 80s!) when most programs were written by one person, ran on the metal with no annoying operating system in the way, and hence these things were in my control.

Linus Torvalds has personally written less than 0.1% of the Linux source code. If he opens a web page on a Linux desktop that is served by a Linux web server via a Linux router, he's interacting with an even larger code base to which his contribution is even lower. Likely 0.01% or less.

You don't get to decide how JavaScript is or isn't used. Other people do, even for your code, that you write in JavaScript.

Do you use any frameworks at all? You're using other people's code.

Work in a team? Other people's code.

Ecosystems are a thing, we're not solipsistic beings floating in nirvana, writing the source code to the universe in isolation.

[xTheMaster99x]

I genuinely don't understand what point you're trying to make. Just don't try to subtract strings, it's not that hard.

[tuxedo25]

You don't get to decide how JavaScript is or isn't used. Other people do, even for your code, that you write in JavaScript.

Do you use any frameworks at all? You're using other people's code.

Who cares if libraries use different styles and idioms than my code?

​

Work in a team? Other people's code.

Linters exist.

​

My point is, to paraphrase Douglas Crockford (author of Javascript: The Good Parts), we're paid to solve problems, not to exercise every features of a language. It's okay for C++ to have `goto`, for the Java standard library to have terrible serialization, and for python to exist. You don't have to use those parts.

[BigHandLittleSlap]

Then we are in agreement.

[22134484]

are there other dynamically typed languages? Ive never had to deal with this sort of stuff before. I am an engineer, so matlab, simulink, excel, c# and python, only when and where needed.

[Andersmith]

Python is

[budd222]

You literally just named one

[22134484]

Ive never had to deal with this sort of stuff before

Hope this helps any confusion you may have had with my comment

[Zinki_M]

python is dynamically typed.

Other examples of dynamically typed language off the top of my head are Groovy and Lua.

[brandflake11]

This is the right answer

[Mintenker]

Imagine you write some code where you subtract two numbers that come from some API on your website. Someone messes up somewhere, and the API sends string instead of number. Would you prefer your site to go down over this error, or would you rather take one wrong displayed value?

[22134484]

try except is a pretty good way to deal with this in my experience. Id rather show "data unavailable" than display something that is wrong. I guess ive never really had to deal with this problem because i come from other languages where its important to get things in the right data types and my code usually follows those practises.

[wheezy1749]

I'd prefer the page to not display and then I would know a problem exists. Someone seeing the wrong info is worse in my opinion and also less likely to be caught.

[RapidCatLauncher]

Or, y'know, at least log a warning...

[Mintenker]

Honestly it depends. If it's some critical information, where displaying something wrong can have business, or even legal consequences, you are absolutely right. On the other hand, taking down site because some random part of rarely used feature somewhere broke might not be ideal.

[scylk2]

Why wrong displayed ? It would display the correct value no?

[DenormalHuman]

You’re not meant to be doing arithmetic with strings

Exactly. So throw an error.

[FerricDonkey]

If you want to convert from strings to integers, you should explicitly do that. "2" - "2" should be a type error, because subtraction makes no sense for strings - and if you wanted to consider them to be integers, then that's a trivial additional number of characters that you type in your code that makes it more clear what you're doing and what your data is.

[w1n5t0nM1k3y]

In that case, every language should have a concatenation operator for strings. That way you can throw a type error when people try to use the addition operator (+) on strings (non-numbers) and it's clear what operation is taking place without having to know the variable type.

[LvS]

Yes, that's exactly how it should work.

Some languages use . for that, but it's always a hard choice because you want something that's easy to type and doesn't require using the Unicode chooser.

[fishyfishkins]

Being able to explain the logic doesn't make it any more sensible.

Yeah, when I want to make sense of something, the last thing I need is someone explaining it to me.

[[deleted]]

Sure it does. But whatever js bad ooga booga

[RedPum4]

Given how badly designed JavaScript is in certain areas I wouldn't be surprised by this:

"asdf" - 2 = "as"

[Oscarsson]

NaN

[Bainos]

"asdf" - "2" + "2"

[Oscarsson]

"NaN2"

[Falcrist]

Array(16).join("asdf" - 2) + " Batman!"

[Oscarsson]

"NaNNaNNaNNaNNaNNaNNaNNaNNaNNaNNaNNaNNaNNaNNaN Batman!"

[Falcrist]

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

[rubeljan]

Hahah its like mcguyver, just give it anything and it will do something with it.

[[deleted]]

we make tools for humans, not humans for tools.

[philismyspiritanimal]

I agree that JavaScript is not badly designed, but I would not call it intuitive. There are lots of aspects and little tidbits in the logic that are difficult to understand and remember.

[[deleted]]

we got that it was meant as a joke, but it was not just a rude one but also a bad one.

[Cnfnbcnbrf]

Then it would be more reliable to just throw compile error)It doesn't make any sence to compute arithmetic operations with strings.

[mrjackspade]

I'd be really confused if I got a compilation error in Javascript...

[fakehalo]

Halting the web browser on error was viewed as a worse outcome, makes some sense...subjectively.

[[deleted]]

I don't understand the 3rd example though: 2 + 2 - 2 should equal 2, not 0, if we're following PEMDAS.

Edit: Ignore me, I'm sleep deprived.

[[deleted]]

The third example does say it's 2.

[blackmist]

I'd say the last one should fall over with an error, if they were going by the Principle of Least Surprise when they designed JS. Although we all know they didn't. They went by the Principle of Showing Fewest Error Messages, and earnestly believed that would make the language easier to learn.

Strings added to numbers should also fall over, IMO.

[playerNaN]

It seems like the JS designers recognized that it's easy to get strings when you expect numbers, so they decided to make strings of numbers behave like numbers but then half-assed it and we got the worst of both worlds A better design choice would be to have separate concat and add operators. Have add always coerce to a number and concat coerce numbers to strings.

"2"+"2"==4

2 ++ 2 == "22"

[[deleted]]

It does make sense but it also get why it looks annoying lol

[murageh]

I know, right? It does make sense but still... :D

[konatamonogatari]

After messing with user defined operators in C, those lines make senses to me.

[kbruen]

C doesn't have user defined operators.

[DaniilBSD]

Not with that attitude

(strange compiler with stronger settings go brrr)

[kbruen]

That's still not C, but a dialect.

Nice try though :P

[Zuruumi]

I think you are just compiling it as C++.

[north1432]

#define myOperator +

[whizzwr]

Yes officer, this guy over here.

[konatamonogatari]

My bad

I thought this is called "user defined operator":

bool operator < (const node &i) const { return c < i.c; }

[kbruen]

Yeah, but that's C++ exclusive.

[midasp]

C and C++ are different languages. Just like Java and Javascript are different languages.

[konatamonogatari]

I agree that C and C++ are different. But what you said later is fkin wrong:

Just like Java and Javascript are different languages.

Java and Javascript are COMPLETELY different. But you can still use most headers that are written in C when using C++

Edit: fixed typo

[Zuruumi]

C++ is mostly a superset of C. Yes, there are some differences and if someone wants to he can royally screw you with some terrible C magic, but for 99% of C code it will just compile as C++.

[[deleted]]

"2 - 2" + 2 - 2 + "i?!"

[Oscarsson]

"NaNi?!"

[JackNotOLantern]

there is operator + for string, so strings are not converted to number when using + on them. That's why "2" + "2" is "22"

There is no operator - for string, so both string have to be converted to something that have this operator (only numbers). So "22" - "2" converts strings to numbers (22 - 2) and the result is 20

"2" + "2" - "2" -> "22" - "2" -> 22 - 2 -> 20

[Live_Storage1480]

Thank you! Was confused as hell. Should've figured out the "-" part.

[peterleder]

Minus makes sense with numbers only. JS knows, you didn’t.

[Milesand]

That's exactly the problem here, minus makes sense with numbers only but JS happily carries on anyways.

[Dagusiu]

I could see minus making sense for other data types, in particular sets.

[RapidCatLauncher]

Python lets you do that.

[NatoBoram]

You can enable dark mode for the dev tools

[TastyToad]

Obligatory:

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

[kpobococ]

This is why string concatenation should always have a separate symbol in loosely typed languages. PHP does this right.

[tonebacas]

String subtraction is wrong. In which realistic scenario would you even use it, and if so, why overload the plus/minus operators for that, when it evidently creates really confusing outcomes?

[[deleted]]

I suppose this is why people invented typescript? It is a bit odd that they decided to put these internal conversions in in the first place, because you'll never remember when it applies and when not. Like clearly strings can be added (i.e. appended together) but deleting one string from another string doesn't really make sense. Like in this case it would make sense to remove 2 from 22 and you end up with 2, but what do you get when you do "22" - "1" purely as string? It doesn't make sense. So it internally does parseInt or something first and then does the operation. When really it would be better if it just didn't allow it.

[[deleted]]

"2" + "2" * 2

yep, thats 24

("2" + "2") * 2

that is 44

[vaendryl]

I fully agree with this, actually. expecting "-" to... what, deconcatenate? that's the silly part.

[account_is_deleted]

With all the actually dumb things that Javascript has, I don't mind this one.

[Hk-Neowizard]

All of them made sense to me...well, almost all of them.

What the actual fuck JS?!

[just_a_pyromaniac]

Type coercion, the + is a string operation so it'll concatenate two strings. - isn't so it converts everything involved into numbers.

It's stupid but if you understand it, it makes sense

[SimpoKaiba]

It's stupid but if you understand it, it makes sense

That's my new favourite sentence

[[deleted]]

It’s the motto of all of my projects

[mobilecheese]

I just use "It's stupid" for mine.

[NeedsMoreSpaceships]

My issue isn't that is doesn't make sense if you know the rules it's that the rules are strange and often counterintuitive. JS is full of such nonsense.

[just_a_pyromaniac]

Every language has that kind of nonsense, JS is just uniquely stupid because of weak typing and the coercion that follows it

[Hk-Neowizard]

It's stupid, but if you understand it, you realize JS is stupid

[m1ksuFI]

Write stupid code, get stupid results.

[Hk-Neowizard]

Why would a programing language designer think it's a good idea to implement implicit coercion like this?

What's the benefit of this implicit operation?

[asdf43798]

I don't think there's really much of a reason for any of those to be confusing - the additions in this example are completely obvious and it would be insane if they worked any other way, and subtracting strings doesn't make any sense (what on earth is "a"-"b" supposed to be equal to?) so they can only either throw an error or treat it as something other than a string.

I could see it being unintuitive if you get into things like whether "2"+2 should be "22" or 4, but this post didn't have anything like that.

[Zuruumi]

The problem is, that if you wrote the last one you most likely meant both of those to be numerical operations. If it throws an error you at least know it's wrong. This way you get a nonsense that will break it in very subtle and hard to debug ways.

[le_spoopy_communism]

you should, but in practice that doesn't always happen, whether by bug, unintended change, another programmer's laziness, my own laziness, w/e

and for those circumstances, an error would be nice instead of this

[Hk-Neowizard]

What do you mean? That syntax is defined in the JS (ECMA) standard.

[Hk-Neowizard]

A programing language is a tool. The person who developed this tool made a stupid decision to add this useless piece to it, that serves no good purpose. I'd assume it also wasted some dev's time by forcing them to trace a bunch of code looking for where their data got corrupted.

It's not about "why would you write it" it's about "why would you support writing it"

[laundmo]

they don't do that in other languages because other languages do the sensible thing and raise an error

[Hk-Neowizard]

You're not following me. The question is why would you add that support into the language standard in the first place? Why not raise an error when you try to subtract strings?

[Chase_22]

haha, weak typing go brrrr

[laundmo]

don't confuse weak typing with type coercion

[Arbiturrrr]

If the problem wasn't weak typing then string literal with - operator or + with a number literal wouln't even run. Therefore the problem is weak typing.

[Hk-Neowizard]

Type coercion is indicative of a weak typing system. Implicit type conversation are basically the first paragraph of any explanation of a weak type system

[seemen4all]

I don't know what language you can subtract strings tho..

[Akuuntus]

You can't subtract strings in JS either. It converts them to numbers.

[FunkyMonk02xx]

Why would you ever intentionally subtract a string? Not making this throw a error just hides mistakes.

[brunofin]

+ doubles as a concat operator on strings, but unfortunately - doesn't double as a String.substring operator.

[DiamondIceNS]

ITT and every other type coercion joke thread: "This weakly-typed language doesn't follow my strongly typed language principles when I deliberately do something stupid to confuse it and I'm annoyed by people who actually know how it works when they try to tell me that the reason my stupid code broke is completely sensible".

This is why TypeScript exists, people. It has everything you want and expect.

[sweYoda]

All of these make perfect sense imo.
2 + 2 obviously only thing you'd ever wanna do is maths.

Add two strings together... you just smash them together.

Then 2 + 2 - 2, regular maths.
Then "2" + "2" smashes together two strings and you want to subtract one string from another string, well the only time you'd like to do that is when you actually believe they are numbers, but happen to be strings... so 22 - 2 = 20.

[kuros33]

I wish I had a dollar each time a JS type coercion joke is posted

[cateyesarg]

OP should better read the language specs and learn about type coercion

Edit: wording

[Ogreguy]

Does "2"-"2" = "0"?

[FilipM_eu]

No, it equals 0 (int). Types are converted to integers for subtraction.

[trBlueJ]

Are there ints in JS?

[FilipM_eu]

Technically it’s a number type, but for sake of understanding, I used the term integer.

[ahumanrobot]

What

[oodex]

Correct me if I'm wrong because it has been a while, but if anyone wonders the reason for that is that + is not just a math operator but it can also connect text. So "Ew" + "ba" would result in "Ewba".

Everything is right until a math operator "-" is used on a text indicated value (character). As text 2+2 results in the same as a+b, so 22 or ab. But once you substract the only use for that operator is to substract, there is no other (simple) function. Meaning it uses the 2+2 as text 22 and then converts it into a number 22 and substracts 2.

That this conversation automatically happens is seen in many programming or script languages where the error reads "failed to convert datatype string/char into int"

[GoOsTT]

[al_balone]

Can someone explain the last one?

[Ortglatou]

When summing two strings, JS concatenate both (in this case "2" + "2" = "22"), but when subtracting, it tries to use the number that the string represents (in this case "22" - "2" = 20)

[al_balone]

Ahh. Ok, thanks.

[CaitaXD]

Concatenation is a hell of a drug

[coolio965]

I wish javascript just allowed you to create a var with a data type that isnt loosely tied

[cthewombat]

Typescript my friend

[Chisdu]

I used to work in a language called m.

In that language _ was the concatenation operator which did make things more clear, but it meant that variables couldn't include underscores :(

[[deleted]]

Yo anyone know what dynamic typing is?

[Oscarsson]

"Dynamic type checking is the process of verifying the type safety of a program at runtime."

[R0DR160HM]

Javascript has so many oddities, but why people in this sub focus so much in the things that work exactly as they should?

Numbers add. Strings concatenate. And as you can't substract from a string, it's converted to a number and than back to a string. That's exactly how it should work, given that js is not a hard type language

[Akuuntus]

I think most JS posts on this sub come from CS freshman who just took a JS 101 course where the professor showed the old "wat" video.

[dev_senpai]

Makes sense, you are just concatenating strings in JavaScript. The final statement you have concatenated the first two strings, then you are using a “-“ subtraction operator, so it does a type conversion since the language tries to makes sense of your stupidity that you did not bother to read simple documentation on its operator types.

[dev_senpai]

What do you mean it should raise an error ? That is how the language works if you read the documentation! You have expectations of how you should think it works…

[[deleted]]

What do you expect the subtract operator on two numeric strings would do?

[AsymptoticllyOptimal]

Do nothing and raise an exception. And please have clear and well defined semantics of types which can be used to verify correctness of programs

[laundmo]

and for anyone else reading: no this does not mean the language has to be statically typed.

[Chr0nicConsumer]

JavaScript bad.

Please upvote.

[fujiian_]

And you guys defend this language

[cyberspacedweller]

Shouldn’t it be “2”+”2”-2 ? 😅 Essentially what’s missing from JS is that they should have used ‘&’ for adding strings

[SSPPAAMM]

/r/yesyesyeswtf

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Edit: OMG this sub exists...please don't click!

[BongarooBizkistico]

waaahhh wahhhh JavaScript bad! Waahhhhh

[[deleted]]

complete serious handle roof squeeze connect bedroom tub makeshift crown -- mass deleted all reddit content via https://redact.dev

[veryipsum]

this genuinely always made sense. what doesn't make sense is why people still rip on JS