Pass function with one argument to array.map using jsfuck

Question

I want to convert following code (ignore console.log) to jsfuck convention where only characters []()!+ are allowed (but here for clarity also numbers and strings with a-Z and 0-9 chars are allowed (wrapped by double quotes) - because conversion such strings/numbers to []()!+ is easy)

console.log(
    [1,2,3,4,5].map(x=>x**2)
)

After partial conversion I have

console.log(
    [1,2,3,4,5]["map"]([]["fill"]["constructor"]("return(2)"))
)

The problem is that I'm unable to pass argument x into map function.

Question: How to convert function x=>x**2 to jsf and pass it as map argument?

(I don't want to use 'eval' like solutions where we put map inside string which will be executed as code e.g. []["fill"]["constructor"]('return [1,2,3,4,5].map(x=>x**2)')() - this is forbidden)

@trincot if you are able to provide not-eval solution - then I will change accepted answer (which I usually not do, but in this case such solution will rule the game) — Kamil Kiełczewski, Aug 27 '20 at 15:08
I doubt I can. I broke my head over it in the past hour or so. — trincot, Aug 27 '20 at 15:08

score 1 · Accepted Answer · answered Aug 27 '20 at 14:36

1

The function constructor takes more than one argument:

 []["fill"]["constructor"]('x', 'return x ** 2;')

answered Aug 27 '20 at 14:36

Jonas Wilms

132,000
20
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Wow - so easy - I'm surprised - and this also works for multi-arguments like `[]["fill"]["constructor"]('x','y','return x*y')(3,4)` – Kamil Kiełczewski Aug 27 '20 at 14:55

score 0 · Answer 2 · answered Sep 01 '20 at 18:59

0

Alternative solution - it also allows to define multi-arg methods

console.log(
  [1,2,3,4,5].map( 
    []["fill"]["constructor"]('return x=>x**2')()
  )
)

answered Sep 01 '20 at 18:59

Kamil Kiełczewski

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345

Pass function with one argument to array.map using jsfuck

2 Answers2

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