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[-] avidamoeba@lemmy.ca 202 points 2 months ago* (last edited 2 months ago)

This is too stupid so I had to check.

Fuck me.

[-] Gsus4@mander.xyz 111 points 2 months ago* (last edited 2 months ago)

Hm, playing devil's advocate, I think it is because the minus has not been defined as a string operation (e.g. it could pop the last char), so it defaults to the mathematical operation and converts both inputs into ints.

The first is assumed to be a concat because one of the parcels is a string...

It's just doing a lot of stuff for you that it shouldn't be in first place 🤭

[-] avidamoeba@lemmy.ca 42 points 2 months ago

Yup. It's completely inconsistent in its interpretation of the + operator.

[-] Gsus4@mander.xyz 19 points 2 months ago* (last edited 2 months ago)

Yeah, I actually had to try 1+"11" to check that it didn't give me 12, but thankfully ~~it commutes~~ it's consistent 😇

[-] palordrolap@fedia.io 19 points 2 months ago

it commutes

Maybe the behaviour with regard to type conversion, but not for the operation itself.

"13"+12 and 12+"13" don't yield the same result.

[-] raspberriesareyummy@lemmy.world 7 points 2 months ago

Nor would I expect "1312" to equal "1213".. Still that operator with these operands should just throw an exception

[-] palordrolap@fedia.io 4 points 2 months ago

Given it's JavaScript, which was expressly designed to carry on regardless, I could see an argument for it returning NaN, (or silently doing what Perl does, like I mention in a different comment) but then there'd have to be an entirely different way of concatenating strings.

[-] raspberriesareyummy@lemmy.world 5 points 2 months ago

Why would you need an entirely different way of concatenating strings? "11" + 1 -> exception. "11" + to_string(1) = "111"

[-] palordrolap@fedia.io 2 points 2 months ago

You're right. I've got too much Perl on the brain and forgot my roots. There is a language that does what you're talking about with the '+' operator: BASIC

Good luck getting the same thing retrofitted into JavaScript though. I can imagine a large number of websites would break or develop mysterious problems if this (mis)behaviour was fixed.

[-] raspberriesareyummy@lemmy.world 1 points 2 months ago

I don't think there's a way to retrofit JS - but php versions are deprecated all the time. Why not do the same with client-side script versions? :)

[-] ChickenLadyLovesLife@lemmy.world 5 points 2 months ago

expressly designed to carry on regardless

I'm surprised they didn't borrow On Error Resume Next from Visual Basic. Which was wrongly considered to be the worst thing in Visual Basic - when the real worst thing was On Error Resume. On Error Resume Next at least moved on to the next line of code when an error occurred; On Error Resume just executed the error-generating line again ... and again ... and again ... and again ...

[-] dalekcaan@lemm.ee 13 points 2 months ago

Yeah, this looks dumb on the surface, but you've got bigger problems if you're trying to do math with strings

[-] Klear@sh.itjust.works 4 points 2 months ago

Better than doing physics with strings

[-] 0x0@lemmy.zip 12 points 2 months ago

It's just doing a lot of stuff for you that it shouldn't be in first place 🤭

Kinda like log4j!

[-] jol@discuss.tchncs.de 37 points 2 months ago

From all the Javascript quiks this is the least stupid and the most obvious.

[-] irelephant@programming.dev 28 points 2 months ago
[-] wasabi@feddit.org 35 points 2 months ago
[-] ChickenLadyLovesLife@lemmy.world 7 points 2 months ago* (last edited 2 months ago)

That is absolutely (n > 1) * ("ba" + 0/0 + "a")

[-] Matombo@feddit.org 7 points 2 months ago

(n > 1) * ("ba" + 0/0 + "a")

Uncaught ReferenceError: n is not defined

?

[-] Gsus4@mander.xyz 2 points 2 months ago
[-] Alexstarfire@lemmy.world 22 points 2 months ago

Unfortunately, it makes sense if you know what + means, which is concatenate. - is strictly a math function though.

Not saying that makes this better. It just makes sense.

[-] grue@lemmy.world 31 points 2 months ago* (last edited 2 months ago)

It is 'comprehensible' in the sense that it's possible to figure out how it happened, but it absolutely does not "make sense" in terms of being a reasonable language design decision. It's 100% incompetence on the part of the person who created Javascript.

[-] Alexstarfire@lemmy.world 8 points 2 months ago

I mean, I'd never try to do this anyway because if the types aren't the same unexpected things can happen. That's like programming 101.

[-] grue@lemmy.world 14 points 2 months ago

Exactly, which is why designing the language to allow it is incompetence.

[-] Alexstarfire@lemmy.world 1 points 2 months ago
[-] raspberriesareyummy@lemmy.world 2 points 2 months ago

Thanks for saving me the typing.

[-] fushuan@lemm.ee 2 points 2 months ago

It makes perfect sense if the Lang objective is to fail as little as possible. It picks the left side object, checks if the operand is a valid operand of the type. If it is, it casts the right variable into that type and perform the operand. If it isn't, it reverses operand positions and tries again.

The issue here is more the fact that + is used both as addition and as concatenation with different data types. Well, not an issue, just some people will complain.

[-] grue@lemmy.world 2 points 2 months ago

Computing a nonsensical result is itself a failure. Continuing to run while avoiding giving an error in that case accomplishes nothing but to make the program harder to debug.

[-] CidVicious@sh.itjust.works 13 points 2 months ago

I think I'm on the side of "if you do this in your code, you deserve what you get."

this post was submitted on 04 Jun 2025
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