JS is a language where [1,2,11].sort() returns [1,11,2].
And if you use a variable instead of a bare array, half the functions are side-effectful, as determined by coin toss.
And if you try declaring that variable with new Array(3).map() then it will ignore all 3 indices, because undefined is real enough to be enumerated, but not real enough to be iterated, because, and I cannot overstress the importance of this principle in Javascript, go fuck yourself. Go fuck yourself is why.
Array(3) doesn’t create [undefined, undefined, undefined, ]; it creates [/* hole */, /* hole */, /* hole */, ]. The holes don’t set any property on the array whatsoever, so they are skipped when iterating. How this makes sense, I can’t tell you.
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x % 2 == 0
If you forget for a second it’s Javascript, the language will turn back and bite you.
(+x) % 2 === 0
what does the +x do.
It makes sure
xis a number.what a wonderful and beautiful language. i’m so glad i asked
And so wonderfully similar to the way that symbol is used in other languages as well. Gosh darn it I love JavaScript
I am not good friends with js, what did I miss?
JS is a language where
[1,2,11].sort()returns[1,11,2].And if you use a variable instead of a bare array, half the functions are side-effectful, as determined by coin toss.
And if you try declaring that variable with
new Array(3).map()then it will ignore all 3 indices, becauseundefinedis real enough to be enumerated, but not real enough to be iterated, because, and I cannot overstress the importance of this principle in Javascript, go fuck yourself. Go fuck yourself is why.typeof(null) == ‘object’
Because some people think planning an entirely new language should take less than 2 weeks. 10 days, in this case.
See wat for more.
Array(3)doesn’t create[undefined, undefined, undefined, ]; it creates[/* hole */, /* hole */, /* hole */, ]. The holes don’t set any property on the array whatsoever, so they are skipped when iterating. How this makes sense, I can’t tell you.Time is a flat circle
Yet the array contains exactly three nothings.
It’s like a zen koan.
We wrote it wrong on purpose, as a joke.
The Wimp Lo doctrine is a valid theory for why JS is Like That.
If there’s two ways to do something, JS picks all three.
This evaluates to NaN for some reason:
Since JS doesn’t really differentiate strings from numbers, except on the places it does, it makes sense to make sure you are working with numbers.
Oh right that. I guess I was visualizing a scenario where you already checked for it being a number, such as a Number.isInteger(x)
also, that suprises me a lot, you’d think this is one of the places where it treats stuff as numbers
Not a JS dev either but
===.Not really sure what the
(+x)is aboutthe remainder operator should return a number or a NaN right? do we actually need the triple here?
Not really. But with JS it’s better safe than sorry.
The GP’s addition is unnecessary, but I fully support anyone that decides to do it.
point taken!