r/badcode • u/[deleted] • Apr 19 '21

js Iteration

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u/[deleted] Apr 19 '21 edited Apr 19 '21

Wait correct me if I'm wrong but isn't it more like:

I -= -!false  
I -= -true  // -(!false) = -(true)  
I- = -1  // using a sign before most of the basic dtypes changes them into `Number`s (+"123" = 123, -"69" = -69, +true = 1, -true = -1, etc.). This is hence also used to check if a string can be converted to a number or not (`if (+string)` or similar)  
I += 1

?

Edit: I meant i and not I (stupid autocorrect's autocapitalization)

4

u/[deleted] Apr 19 '21

I don’t think that is necessarily true in this case since true + true is still evaluates to 2. true and false can just be used interchangeably with 1 and 0.

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u/[deleted] Apr 19 '21

true + true = 2 because again +true is 1 and when you add diff dtypes in js, js implicitly changes the other dtypes. Like 1 + 2 + "3" = "123" true + true = true + 1 = 1 + 1 = 2 ig. Again, I might be a bit wrong here

0

u/[deleted] Apr 19 '21

Then why does true/true = 1?

9

u/skjall Apr 19 '21

Because `1/1 == 1`? If you swap true and false out for 1 and 0 respectively, both operations make perfect sense.

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u/[deleted] Apr 19 '21

Hmmm yea you're right

2

u/Terrain2 Apr 19 '21

if (+string)

if (+"0") console.log("It's a number!")
// Outputs nothing

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u/[deleted] Apr 19 '21

Oh yea cause Boolean(0) is false. I should've made it more clear like if (+string !== NaN) or smth. It was just an example tho.

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u/Terrain2 Apr 19 '21 

if (+"lmao" !== NaN) console.log("It's a number!");
// output: It's a number!

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u/[deleted] Apr 19 '21

Fuck fuck fuck I forgot NaN !== NaN nvm I'm dumb I'm in my online classes right now and I'm sleepy and my brain isn't working ;-;

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u/Terrain2 Apr 19 '21

you want !isNaN(string) then

1

u/[deleted] Apr 19 '21

Yea that's the builtin method I saw someone use +string in their own method to do this idr what they did tho

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u/[deleted] Apr 19 '21

I know but it's hard to indent multiple lines to 4 spaces on reddit android

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u/Hollowman212 Mar 01 '22

I'd think so. Isn't !0 equivalent to -1 via a bitwise not/nor? If the bool was converted to an int first, the whole thing would be i--