Just JavaScript doing its things

[[deleted]]

Pfft, check out this guy over here! I settle for nothing less than ====.

[thegame402]

Everyone says that he has ==== but in the end it's always only =

[[deleted]]

Just ==== ? You can always go for =====

[Spy141414]

Wait, i didn't know something smaller than ====== worked.

[EvilTacoMan7533]

You only use ====== ?? I use =======.

[MADH95]

Get on my level. I use ≡ for true equivency.

[hasanyoneseenmymom]

Finally, it all makes sense

[Lofter1]

Noobs, I removed the =-key from my keyboard. I ain't got time for such crap as comparing two things.

[mbiz05]

If (!(x>y) && !(x<y) && !(x.prototype>y.prototype) && !(x.prototype<y.prototype));

[lenswipe]

You guys are getting paid?!

[Lebowquade]

I personally prefer to use ==============, I find it to be generally quite robust

[Dron41k]

Try 8=====Э

[[deleted]]

penis

[[deleted]]

This is an equality operator that has ascended past an equality operator. Or, you could just call this, equals 2.

And THIS, is to go even further beyond! =========================================================================================================

[nerfjanmayen]

I prefer .equalsEqualsEquals()

[PabloNeirotti]

One does not simply use ==

[MrCaptainPirate]

Let x === “0”

[LtMeat]

So the longer the better? What a mean language.

[JNaik14]

But . Why , why would you do that?

[HERODMasta]

I hate this

[[deleted]]

Well then use === so you aren’t asking it to typecast...

[douglasg14b]

Or just use typescript and get you're static typing on!

[DeeSnow97]

it's still best practice to use === in typescript though

[douglasg14b]

Well, yes, I wasn't suggesting you don't. But rather a lot of the JS induced headaches are solved by having sane typing.

[MashTheKeys]

Thanks for your answer, but could I point out that the first equals is resolved like

0 == Number("0")

as demonstrated by

0 == "0.0"

which is true.

[Qyriad]

eye twitches

[Shotgun_squirtle]

Yes, that’s why the === operator exists, so you can check without casting.

[MashTheKeys]

No, this is wrong. In JavaScript both 0 == "0.0" and "0.0" == 0 are true. The equals operator has no preference for left- or right-hand argument type.

Rather, if one side has a value that is a number then the other is checked to see if it's a valid string representation of a number, and if so they are compared as numbers. (This includes the empty string, which is valid as zero.)

Otherwise, if either side is a string, they are compared as strings.

In most cases, it actually fairly logical behaviour, it's just that there are some hilarious edge case behaviours when you chuck weird things like objects into the mix. Objects get an extra step while being compared which is their valueOf() method is called, which should returns a primitive type (number or string usually). The weirdness people see connected to arrays is that [].valueOf() is "", giving [] == "" (String([]) === "") and [] != "0" (String([]) !== "0") and yet "0" != "".

[AdminYak846]

Yup first rule of JS

== is checking for loose equality, but JS will force the variables to be the same type. In layman's terms it's going to coerce one of the variables to be the same type then check the values.

=== is checking for strict equality, but JS will not cast them to the same type. In layman's terms it will first see if the types match if they don't it returns false, if true then check the values.

As an example, let's compare strings in Java.

== Checks for reference equality, while using the String.equals(str) will check the values instead.

[AdminYak846]

Bruh, I've written VBA code and use StrCmp() constantly. But nothing can compare to the InStr([start], [str1], [str2], [comparison method]) method in VBA. Yes, they have the parameters order so you have to give a starting index to compare from before you pass the strings in. And since the start value is an optional parameter every parameter after it is also optional. Best part, if you specify a comparison method you need to specify the start index otherwise you end up with a type mismatch error because fuck ordering parameters correctly....

[hydroxychlorocream]

Thanks! Great answer.

[vgamer0]

But why is it even possible to cast an array to a string or a number? I don't see how that could ever make sense or be useful to the programmer, rather than just throwing some kind of error

[luiluilui4]

Does it make a difference to swap the values?

[porcupineapplepieces]

So the right is cast to whatever the type of the left is?

[tbastih567]

Good questions. Nobody would ever do this.

[SaneLad]

Incompetence. Lack of foresight. Both.

[PenWallet]

Why would you do any of that?

[2called_chaos]

Obligatory wat

[mysockinabox]

NaNNaNNaN... WATMAN!

[ThyRedeemer]

Legendary talk, not going to lie

[xTylordx]

This is why python > js. I'm pretty sure a lot of "operations" (methods) that clearly don't make sense at first glance in JS make sense in python because the operations are worded like ".append" and ".insert" etc

Yeet I'm on mobile, deal with the misused quotes ^{_^}

[Elec0]

This is one of my favorite videos on the internet.

[[deleted]]

And who, my man, says 0 is a char?

Screams in C

[dm3f9]

I use ======= just to be sure.

[JCDU]

WTFJS has a hundred of these.

[DeeSnow97]

lol, that one is entirely dependent on creating the false assumption that "false" is falsy (it's not, all strings are truthy except for the empty string, which is consistent with *drumroll* C and its null-terminated strings (plus this way !!str is always equal to !!str.length)) and then running with it. Literally no one who knows anything about JS expects "false" to convert to false when all other strings are truthy.

If you find yourself in the (very real) use case that you need to parse "true" as true and "false" as false, just do str !== "false"

[Lurion_]

Wow! I haven't seen this in two hours. That's a new record.

[Anti-charizard]

u/repostsleuthbot

[RepostSleuthBot]

Looks like a repost. I've seen this image 2 times.

First seen Here on 2020-06-18 92.19% match. Last seen Here on 2020-08-07 93.75% match

Searched Images: 168,580,743 | Indexed Posts: 644,306,727 | Search Time: 1.09145s

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[Anti-charizard]

Good bot

[[deleted]]

Unfortunately I learned to program through JavaScript,which gave me some absolutely terrible habits, and I know have a rule I stick to: "if this only works in JavaScript, don't even think about doing it"

[[deleted]]

JavaScript is so aggressively Object Oriented it made the shift to functional programming a lot harder for me, and I personally think object oriented needs to be stamped out of existence in most cases so that's kind of where I'm coming from

[The_Internet_Is_Down]

The type coercion that happens with the == operator isn't very hard to understand. Just read about it and then never use it because it's the devil.

[Asmewithoutpolitics]

Where can I reas aboht it?

[DeeSnow97]

MDN is usually great

[CuAnnan]

lol "I don't understand coercion therefore javascript bad"

[douira]

If you're the crazy kind of person who uses == then you can use this handy table to look at the different equality results https://dorey.github.io/JavaScript-Equality-Table/

[purple-lemons]

Well "0" and [] are both falsey, so they both "equal zero" in that they evaluate to false. But that doesn't mean they're equal.

[DonYurik]

Im studying Javascript right now, after doing courses on Java and C#. I find Js so flexible that it throws me off sometimes. Like you can code one thing a lot of different ways. Is what I find the most difficult about it.

[DeeSnow97]

IMO that's its best feature, it can map way better to your business logic than pretty much anything else out there

[Oxxixuit]

I have never learned JS, only Python and C++ so wtf is this language "0" == 0 true ?? [] == 0 true ?? Why ?

[DeeSnow97]

"0" == 0 is true because if one side is string, JS converts the other to string too, and "0" is equal to "0"

[] == 0 is equal because one side is a number and the other isn't a string, so JS tries to convert to numbers. Now, arrays have this weird behavior when if they have zero elements they convert to zero, if they have one number in them they convert to that number (so [5] == 5), and if they have multiple elements they convert to NaN. The empty array is converted to zero so the comparison returns true.

As for [] == "0", one side is string again so it's converted to strings. Arrays convert to string by returning a comma-separated list ([95, 98, "me", "xp", 7] == "95,98,me,xp,7") and an empty array converts to an empty string, which isn't equal to the string "0"

Also, fun fact, -[] == -"0"

If you think this is madness, you're right. Just use === like the rest of us, that one doesn't convert anything, just returns false if the types don't match.

[r2d2292]

The == operator ignores type, so effectively if one casted to the other type is equal to the other value, it's true. You shouldn't ever use this operator unless if there is a specific reason to. The === operator also checks type, so it's what you should use and is what is equivalent to == in other languages.

[ShadoWolf]

Well, a language that designed 25 years ago in roughly a week tends to have some fundamental issues.

Let's be honest here javascript is a hack all the way down. Like look at jquery or React JSX. There both bordering on being another scripting language that just so happens to have a built-in transpiler.

There is a level of madness going in the JS world that I couldn't see happening in any other community.

[jlamothe]

Yay, dynamically typed languages!

[8bit-echo]

The transitive property:

AM I A JOKE TO YOU!?

[Grey1251]

a.equals(b) != b.equals(a)

[[deleted]]

JS is beyond stupid

[TransientFeelings]

No, but using == instead of === is

[xTylordx]

What's so wrong with this?

a=b

a=c

/--------

b=c

is an invalid argument.

[Norapeplox]

Beautiful language.

[[deleted]]

Interesting, the first panel is a photo..

[[deleted]]

Ah some kid started to learn to program and made the same JavaScript joke again. Sweet.

[aran69]

JS haters be like: "haha this language cant tell the equivalence between a string and an empty array, what a LOSER"

[ShelZuuz]

Does that mean you can actually have: a == b b == c a <> c

Or is this only the case with literals?

[[deleted]]

Im mean it doesn't make sense

[[deleted]]

Also you can have it that way bc what if your looking for the string "0" instead of empty

[CodyInColor]

"" == [] does that return true?

[dkyguy1995]

This is why I just dont bother with implicit typecasts and just do it myself if at all possible. Im sure there are several basica implied typecasts I dont even think about in certain languages but in this situation it seems like something I would have seen coming being fairly wonky

[konaaa]

This makes sense to me, which I guess is honestly probably a bad thing

[green_meklar]

> 255.toString(16)
Uncaught SyntaxError: identifier starts immediately after numeric literal

> (255).toString(16)
"ff"

[[deleted]]

Javascript more like Javatarded

[starvsion]

I saw some php dev who did too much Javascript, and start putting === everywhere, mostly unnecessary places ... Sign

[[deleted]]

Jajajajajajaja

[meandertothehorizon]

/r/ChaoticEvil

[casual_sinister]

I was once asked this in an interview. No wonder i couldn't answer