JSFuck variant using "([+<])". Has anybody tried this before?

[baboures]

I don't know if anybody has ever done this before. I made a JSFuck variant using < instead of !.

JSFuckr: An esoteric language based on JSFuck

Try it!

Is this a novel idea, or I am reinventing the wheel? 😅

[kamil-kielczewski]

@baboures what are advantages of using < instead ! ?

For instance - for generate some letters JSFuck use deprecated methods like italics (which can be avoid but produce extremely long code) - are < is free of this?

https://stackoverflow.com/questions/63673610/alternative-way-to-get-c-letter-in-jsfuck

[baboures]

@kamil-kielczewski < also serves as a bitwise left shift operator <<. See this example: https://github.com/aemkei/jsfuck#numbers

However, I don't think using a left shift operator to generate numbers will lead to a shorter outcome for this specific charset.

4 = ([]<[+[]])<<([]<[+[]])<<([]<[+[]]) (34 chars)
4 = !+[]+!+[]+!+[]+!+[] (19 chars)

8 = ([]<[+[]])<<([]<[+[]])<<([]<[+[]])<<([]<[+[]]) (46 chars)
8 = !+[]+!+[]+!+[]+!+[]+!+[]+!+[]+!+[]+!+[] (39 chars)

PD: I also considered using the charset [(+=)]:

'false':      '[]==[]',
'true':       '[]==+[]',
'undefined':  '[][[]]',
'NaN':        '+[][[]]',

which is much worse than in the original JSFuck:

'false':      '![]',
'true':       '!![]',
'undefined':  '[][[]]',
'NaN':        '+[![]]',

so, all in all, []()!+ is the optimal charset.

Ultimately, my goal wasn't to beat the original JSFuck charset, but to find new exotic ways of writing JavaScript.
I decided to make a compiler for the charset ([+<]) just because it looks really cool 😎

[kamil-kielczewski]

@baboures new exotic way is ok. However - can you show here how to produce letter C using ([+<]) ? (show intermediate steps and final form which use only ([+<]) )

[baboures]

@kamil-kielczewski The process is exactly the same as the original JSFuck. In fact, I just made a few changes to aemkei's compiler in order to switch to the ([+<]) charset. I will show step-by-step how to manually produce the letter C for educational purposes, although this is one of the hardest chars.

Show spoiler

---

C: escape("".italics())[2]

Since escape is a global function (i.e. it is a property of window), we can only get it via Function("return escape")():

Function("return escape")()(("")["italics"]())[2]

Let's start with the easy part: 2 can be rewritten as ([]<[+[]])+([]<[+[]]). So we have:

Function("return escape")()(("")["italics"]())[([]<[+[]])+([]<[+[]])]

Another easy one: the empty string "" alone can be translated into []+[]:

Function("return escape")()(([]+[])["italics"]())[([]<[+[]])+([]<[+[]])]. Now we continue with the letters:

r: (true+"")[1], true is ([]<[+[]]) and 1 is +([]<[+[]]). Also, bear in mind anything+"" is equivalent to anything+[].
r: (([]<[+[]])+[])[+([]<[+[]])]

e: (true+"")[3], 3 is ([]<[+[]])+([]<[+[]])+([]<[+[]]), so:
e: (([]<[+[]])+[])[([]<[+[]])+([]<[+[]])+([]<[+[]])]

t: (true+"")[0], 0 is +[], so:
t: (([]<[+[]])+[])[+[]]

u: (undefined+"")[0], undefined is [][[]], so:
u: ([][[]]+[])[+[]]

r: (we already have it)

n: (undefined+"")[1]
n: ([][[]]+[])[+([]<[+[]])]

: (NaN+[]["flat"])[11], NaN is +[[]<[]], 11 is +([]<[+[]])+[+([]<[+[]])], so:
: (+[[]<[]]+[]["flat"])[+([]<[+[]])+[+([]<[+[]])]],

and let's see flat:

f: (false+"")[0], where false is ([]<[])
f: (([]<[])+[])[+[]]

l: (false+"")[2]
l: (([]<[])+[])[([]<[+[]])+([]<[+[]])]

a: (false+"")[1]
a: (([]<[])+[])[+([]<[+[]])]

t: (true+"")[0]
t: (([]<[+[]])+[])[+[]]

So, we have:

flat = f+l+a+t = (([]<[])+[])[+[]]+(([]<[])+[])[([]<[+[]])+([]<[+[]])]+(([]<[])+[])[+([]<[+[]])]+(([]<[+[]])+[])[+[]]

Therefore:

: (+[[]<[]]+[][(([]<[])+[])[+[]]+(([]<[])+[])[([]<[+[]])+([]<[+[]])]+(([]<[])+[])[+([]<[+[]])]+(([]<[+[]])+[])[+[]]])[+([]<[+[]])+[+([]<[+[]])]]

Now, let's start with the string escape:

e: (we already have it)

s: (false+"")[3]
s: (([]<[])+[])[([]<[+[]])+([]<[+[]])+([]<[+[]])]

c: ([]["flat"]+"")[3]
c: ([][(([]<[])+[])[+[]]+(([]<[])+[])[([]<[+[]])+([]<[+[]])]+(([]<[])+[])[+([]<[+[]])]+(([]<[+[]])+[])[+[]]]+[])[([]<[+[]])+([]<[+[]])+([]<[+[]])]

a: (we already have it)

p: (+(211))["to"+String["name"]](31)[1]. Let's start with the numbers:

211: ([]<[+[]])+([]<[+[]])+[+([]<[+[]])]+[+([]<[+[]])]
31: ([]<[+[]])+([]<[+[]])+([]<[+[]])+[+([]<[+[]])]
1: +([]<[+[]])

Now the strings to and name:

t: (([]<[+[]])+[])[+[]] (we already have it)
o: (true+[]["flat"])[10], 10 is +([]<[+[]])+[+[]] and we have the rest so:
o: (([]<[+[]])+[][(([]<[])+[])[+[]]+(([]<[])+[])[([]<[+[]])+([]<[+[]])]+(([]<[])+[])[+([]<[+[]])]+(([]<[+[]])+[])[+[]]])[+([]<[+[]])+[+[]]]

n: (we already have it)
a: (we already have it)
m: (Number+"")[11], 11 is +([]<[+[]])+[+([]<[+[]])], and we can get the constructor Number with (+[])["constructor"]. We already have all the letters that make up the string constructor:

constructor = c+o+n+s+t+r+u+c+t+o+r = ([][(([]<[])+[])[+[]]+(([]<[])+[])[([]<[+[]])+([]<[+[]])]+(([]<[])+[])[+([]<[+[]])]+(([]<[+[]])+[])[+[]]]+[])[([]<[+[]])+([]<[+[]])+([]<[+[]])]+(([]<[+[]])+[][(([]<[])+[])[+[]]+(([]<[])+[])[([]<[+[]])+([]<[+[]])]+(([]<[])+[])[+([]<[+[]])]+(([]<[+[]])+[])[+[]]])[+([]<[+[]])+[+[]]]+([][[]]+[])[+([]<[+[]])]+(([]<[])+[])[([]<[+[]])+([]<[+[]])+([]<[+[]])]+(([]<[+[]])+[])[+[]]+(([]<[+[]])+[])[+([]<[+[]])]+([][[]]+[])[+[]]+([][(([]<[])+[])[+[]]+(([]<[])+[])[([]<[+[]])+([]<[+[]])]+(([]<[])+[])[+([]<[+[]])]+(([]<[+[]])+[])[+[]]]+[])[([]<[+[]])+([]<[+[]])+([]<[+[]])]+(([]<[+[]])+[])[+[]]+(([]<[+[]])+[][(([]<[])+[])[+[]]+(([]<[])+[])[([]<[+[]])+([]<[+[]])]+(([]<[])+[])[+([]<[+[]])]+(([]<[+[]])+[])[+[]]])[+([]<[+[]])+[+[]]]+(([]<[+[]])+[])[+([]<[+[]])]

Thus,

m: (Number+"")[11]
m: (Number+"")[+([]<[+[]])+[+([]<[+[]])]]
m: (Number+[])[+([]<[+[]])+[+([]<[+[]])]]
m: ((+[])["constructor"]+[])[+([]<[+[]])+[+([]<[+[]])]]
m: ((+[])[([][(([]<[])+[])[+[]]+(([]<[])+[])[([]<[+[]])+([]<[+[]])]+(([]<[])+[])[+([]<[+[]])]+(([]<[+[]])+[])[+[]]]+[])[([]<[+[]])+([]<[+[]])+([]<[+[]])]+(([]<[+[]])+[][(([]<[])+[])[+[]]+(([]<[])+[])[([]<[+[]])+([]<[+[]])]+(([]<[])+[])[+([]<[+[]])]+(([]<[+[]])+[])[+[]]])[+([]<[+[]])+[+[]]]+([][[]]+[])[+([]<[+[]])]+(([]<[])+[])[([]<[+[]])+([]<[+[]])+([]<[+[]])]+(([]<[+[]])+[])[+[]]+(([]<[+[]])+[])[+([]<[+[]])]+([][[]]+[])[+[]]+([][(([]<[])+[])[+[]]+(([]<[])+[])[([]<[+[]])+([]<[+[]])]+(([]<[])+[])[+([]<[+[]])]+(([]<[+[]])+[])[+[]]]+[])[([]<[+[]])+([]<[+[]])+([]<[+[]])]+(([]<[+[]])+[])[+[]]+(([]<[+[]])+[][(([]<[])+[])[+[]]+(([]<[])+[])[([]<[+[]])+([]<[+[]])]+(([]<[])+[])[+([]<[+[]])]+(([]<[+[]])+[])[+[]]])[+([]<[+[]])+[+[]]]+(([]<[+[]])+[])[+([]<[+[]])]]+[])[+([]<[+[]])+[+([]<[+[]])]]

e: (we already have it)

so the letter p looks like this:

p: (+(211))["to"+String["name"]](31)[1]
p: (+(([]<[+[]])+([]<[+[]])+[+([]<[+[]])]+[+([]<[+[]])]))[(([]<[+[]])+[])[+[]]+(([]<[+[]])+[][(([]<[])+[])[+[]]+(([]<[])+[])[([]<[+[]])+([]<[+[]])]+(([]<[])+[])[+([]<[+[]])]+(([]<[+[]])+[])[+[]]])[+([]<[+[]])+[+[]]]+([]+[])[([][(([]<[])+[])[+[]]+(([]<[])+[])[([]<[+[]])+([]<[+[]])]+(([]<[])+[])[+([]<[+[]])]+(([]<[+[]])+[])[+[]]]+[])[([]<[+[]])+([]<[+[]])+([]<[+[]])]+(([]<[+[]])+[][(([]<[])+[])[+[]]+(([]<[])+[])[([]<[+[]])+([]<[+[]])]+(([]<[])+[])[+([]<[+[]])]+(([]<[+[]])+[])[+[]]])[+([]<[+[]])+[+[]]]+([][[]]+[])[+([]<[+[]])]+(([]<[])+[])[([]<[+[]])+([]<[+[]])+([]<[+[]])]+(([]<[+[]])+[])[+[]]+(([]<[+[]])+[])[+([]<[+[]])]+([][[]]+[])[+[]]+([][(([]<[])+[])[+[]]+(([]<[])+[])[([]<[+[]])+([]<[+[]])]+(([]<[])+[])[+([]<[+[]])]+(([]<[+[]])+[])[+[]]]+[])[([]<[+[]])+([]<[+[]])+([]<[+[]])]+(([]<[+[]])+[])[+[]]+(([]<[+[]])+[][(([]<[])+[])[+[]]+(([]<[])+[])[([]<[+[]])+([]<[+[]])]+(([]<[])+[])[+([]<[+[]])]+(([]<[+[]])+[])[+[]]])[+([]<[+[]])+[+[]]]+(([]<[+[]])+[])[+([]<[+[]])]][([][[]]+[])[+([]<[+[]])]+(([]<[])+[])[+([]<[+[]])]+((+[])[([][(([]<[])+[])[+[]]+(([]<[])+[])[([]<[+[]])+([]<[+[]])]+(([]<[])+[])[+([]<[+[]])]+(([]<[+[]])+[])[+[]]]+[])[([]<[+[]])+([]<[+[]])+([]<[+[]])]+(([]<[+[]])+[][(([]<[])+[])[+[]]+(([]<[])+[])[([]<[+[]])+([]<[+[]])]+(([]<[])+[])[+([]<[+[]])]+(([]<[+[]])+[])[+[]]])[+([]<[+[]])+[+[]]]+([][[]]+[])[+([]<[+[]])]+(([]<[])+[])[([]<[+[]])+([]<[+[]])+([]<[+[]])]+(([]<[+[]])+[])[+[]]+(([]<[+[]])+[])[+([]<[+[]])]+([][[]]+[])[+[]]+([][(([]<[])+[])[+[]]+(([]<[])+[])[([]<[+[]])+([]<[+[]])]+(([]<[])+[])[+([]<[+[]])]+(([]<[+[]])+[])[+[]]]+[])[([]<[+[]])+([]<[+[]])+([]<[+[]])]+(([]<[+[]])+[])[+[]]+(([]<[+[]])+[][(([]<[])+[])[+[]]+(([]<[])+[])[([]<[+[]])+([]<[+[]])]+(([]<[])+[])[+([]<[+[]])]+(([]<[+[]])+[])[+[]]])[+([]<[+[]])+[+[]]]+(([]<[+[]])+[])[+([]<[+[]])]]+[])[+([]<[+[]])+[+([]<[+[]])]]+(([]<[+[]])+[])[([]<[+[]])+([]<[+[]])+([]<[+[]])]]](([]<[+[]])+([]<[+[]])+([]<[+[]])+[+([]<[+[]])])[+([]<[+[]])]

As for the string italics, we have everything except the i.

i: ([false]+undefined)[10]
i: ([false]+undefined)[+([]<[+[]])+[+[]]]
i: ([false]+[][[]])[+([]<[+[]])+[+[]]]
i: ([false]+[][[]])[+([]<[+[]])+[+[]]]
i: ([([]<[])]+[][[]])[+([]<[+[]])+[+[]]]

Finally, the Function constructor can be obtained like this:

Function: []["flat"]["constructor"]
Function: [][(([]<[])+[])[+[]]+(([]<[])+[])[([]<[+[]])+([]<[+[]])]+(([]<[])+[])[+([]<[+[]])]+(([]<[+[]])+[])[+[]]][([][(([]<[])+[])[+[]]+(([]<[])+[])[([]<[+[]])+([]<[+[]])]+(([]<[])+[])[+([]<[+[]])]+(([]<[+[]])+[])[+[]]]+[])[([]<[+[]])+([]<[+[]])+([]<[+[]])]+(([]<[+[]])+[][(([]<[])+[])[+[]]+(([]<[])+[])[([]<[+[]])+([]<[+[]])]+(([]<[])+[])[+([]<[+[]])]+(([]<[+[]])+[])[+[]]])[+([]<[+[]])+[+[]]]+([][[]]+[])[+([]<[+[]])]+(([]<[])+[])[([]<[+[]])+([]<[+[]])+([]<[+[]])]+(([]<[+[]])+[])[+[]]+(([]<[+[]])+[])[+([]<[+[]])]+([][[]]+[])[+[]]+([][(([]<[])+[])[+[]]+(([]<[])+[])[([]<[+[]])+([]<[+[]])]+(([]<[])+[])[+([]<[+[]])]+(([]<[+[]])+[])[+[]]]+[])[([]<[+[]])+([]<[+[]])+([]<[+[]])]+(([]<[+[]])+[])[+[]]+(([]<[+[]])+[][(([]<[])+[])[+[]]+(([]<[])+[])[([]<[+[]])+([]<[+[]])]+(([]<[])+[])[+([]<[+[]])]+(([]<[+[]])+[])[+[]]])[+([]<[+[]])+[+[]]]+(([]<[+[]])+[])[+([]<[+[]])]]

So, putting everything together we get this beast for the character C:

[][(([]<[])+[])[+[]]+(([]<[])+[])[([]<[+[]])+([]<[+[]])]+(([]<[])+[])[+([]<[+[]])]+(([]<[+[]])+[])[+[]]][([][(([]<[])+[])[+[]]+(([]<[])+[])[([]<[+[]])+([]<[+[]])]+(([]<[])+[])[+([]<[+[]])]+(([]<[+[]])+[])[+[]]]+[])[([]<[+[]])+([]<[+[]])+([]<[+[]])]+(([]<[+[]])+[][(([]<[])+[])[+[]]+(([]<[])+[])[([]<[+[]])+([]<[+[]])]+(([]<[])+[])[+([]<[+[]])]+(([]<[+[]])+[])[+[]]])[+([]<[+[]])+[+[]]]+([][[]]+[])[+([]<[+[]])]+(([]<[])+[])[([]<[+[]])+([]<[+[]])+([]<[+[]])]+(([]<[+[]])+[])[+[]]+(([]<[+[]])+[])[+([]<[+[]])]+([][[]]+[])[+[]]+([][(([]<[])+[])[+[]]+(([]<[])+[])[([]<[+[]])+([]<[+[]])]+(([]<[])+[])[+([]<[+[]])]+(([]<[+[]])+[])[+[]]]+[])[([]<[+[]])+([]<[+[]])+([]<[+[]])]+(([]<[+[]])+[])[+[]]+(([]<[+[]])+[][(([]<[])+[])[+[]]+(([]<[])+[])[([]<[+[]])+([]<[+[]])]+(([]<[])+[])[+([]<[+[]])]+(([]<[+[]])+[])[+[]]])[+([]<[+[]])+[+[]]]+(([]<[+[]])+[])[+([]<[+[]])]]((([]<[+[]])+[])[+([]<[+[]])]+(([]<[+[]])+[])[([]<[+[]])+([]<[+[]])+([]<[+[]])]+(([]<[+[]])+[])[+[]]+([][[]]+[])[+[]]+(([]<[+[]])+[])[+([]<[+[]])]+([][[]]+[])[+([]<[+[]])]+(+[[]<[]]+[][(([]<[])+[])[+[]]+(([]<[])+[])[([]<[+[]])+([]<[+[]])]+(([]<[])+[])[+([]<[+[]])]+(([]<[+[]])+[])[+[]]])[+([]<[+[]])+[+([]<[+[]])]]+(([]<[+[]])+[])[([]<[+[]])+([]<[+[]])+([]<[+[]])]+(([]<[])+[])[([]<[+[]])+([]<[+[]])+([]<[+[]])]+([][(([]<[])+[])[+[]]+(([]<[])+[])[([]<[+[]])+([]<[+[]])]+(([]<[])+[])[+([]<[+[]])]+(([]<[+[]])+[])[+[]]]+[])[([]<[+[]])+([]<[+[]])+([]<[+[]])]+(([]<[])+[])[+([]<[+[]])]+(+(([]<[+[]])+([]<[+[]])+[+([]<[+[]])]+[+([]<[+[]])]))[(([]<[+[]])+[])[+[]]+(([]<[+[]])+[][(([]<[])+[])[+[]]+(([]<[])+[])[([]<[+[]])+([]<[+[]])]+(([]<[])+[])[+([]<[+[]])]+(([]<[+[]])+[])[+[]]])[+([]<[+[]])+[+[]]]+([]+[])[([][(([]<[])+[])[+[]]+(([]<[])+[])[([]<[+[]])+([]<[+[]])]+(([]<[])+[])[+([]<[+[]])]+(([]<[+[]])+[])[+[]]]+[])[([]<[+[]])+([]<[+[]])+([]<[+[]])]+(([]<[+[]])+[][(([]<[])+[])[+[]]+(([]<[])+[])[([]<[+[]])+([]<[+[]])]+(([]<[])+[])[+([]<[+[]])]+(([]<[+[]])+[])[+[]]])[+([]<[+[]])+[+[]]]+([][[]]+[])[+([]<[+[]])]+(([]<[])+[])[([]<[+[]])+([]<[+[]])+([]<[+[]])]+(([]<[+[]])+[])[+[]]+(([]<[+[]])+[])[+([]<[+[]])]+([][[]]+[])[+[]]+([][(([]<[])+[])[+[]]+(([]<[])+[])[([]<[+[]])+([]<[+[]])]+(([]<[])+[])[+([]<[+[]])]+(([]<[+[]])+[])[+[]]]+[])[([]<[+[]])+([]<[+[]])+([]<[+[]])]+(([]<[+[]])+[])[+[]]+(([]<[+[]])+[][(([]<[])+[])[+[]]+(([]<[])+[])[([]<[+[]])+([]<[+[]])]+(([]<[])+[])[+([]<[+[]])]+(([]<[+[]])+[])[+[]]])[+([]<[+[]])+[+[]]]+(([]<[+[]])+[])[+([]<[+[]])]][([][[]]+[])[+([]<[+[]])]+(([]<[])+[])[+([]<[+[]])]+((+[])[([][(([]<[])+[])[+[]]+(([]<[])+[])[([]<[+[]])+([]<[+[]])]+(([]<[])+[])[+([]<[+[]])]+(([]<[+[]])+[])[+[]]]+[])[([]<[+[]])+([]<[+[]])+([]<[+[]])]+(([]<[+[]])+[][(([]<[])+[])[+[]]+(([]<[])+[])[([]<[+[]])+([]<[+[]])]+(([]<[])+[])[+([]<[+[]])]+(([]<[+[]])+[])[+[]]])[+([]<[+[]])+[+[]]]+([][[]]+[])[+([]<[+[]])]+(([]<[])+[])[([]<[+[]])+([]<[+[]])+([]<[+[]])]+(([]<[+[]])+[])[+[]]+(([]<[+[]])+[])[+([]<[+[]])]+([][[]]+[])[+[]]+([][(([]<[])+[])[+[]]+(([]<[])+[])[([]<[+[]])+([]<[+[]])]+(([]<[])+[])[+([]<[+[]])]+(([]<[+[]])+[])[+[]]]+[])[([]<[+[]])+([]<[+[]])+([]<[+[]])]+(([]<[+[]])+[])[+[]]+(([]<[+[]])+[][(([]<[])+[])[+[]]+(([]<[])+[])[([]<[+[]])+([]<[+[]])]+(([]<[])+[])[+([]<[+[]])]+(([]<[+[]])+[])[+[]]])[+([]<[+[]])+[+[]]]+(([]<[+[]])+[])[+([]<[+[]])]]+[])[+([]<[+[]])+[+([]<[+[]])]]+(([]<[+[]])+[])[([]<[+[]])+([]<[+[]])+([]<[+[]])]]](([]<[+[]])+([]<[+[]])+([]<[+[]])+[+([]<[+[]])])[+([]<[+[]])]+(([]<[+[]])+[])[([]<[+[]])+([]<[+[]])+([]<[+[]])])()(([]+[])[([([]<[])]+[][[]])[+([]<[+[]])+[+[]]]+(([]<[+[]])+[])[+[]]+(([]<[])+[])[+([]<[+[]])]+(([]<[])+[])[([]<[+[]])+([]<[+[]])]+([([]<[])]+[][[]])[+([]<[+[]])+[+[]]]+([][(([]<[])+[])[+[]]+(([]<[])+[])[([]<[+[]])+([]<[+[]])]+(([]<[])+[])[+([]<[+[]])]+(([]<[+[]])+[])[+[]]]+[])[([]<[+[]])+([]<[+[]])+([]<[+[]])]+(([]<[])+[])[([]<[+[]])+([]<[+[]])+([]<[+[]])]]())[([]<[+[]])+([]<[+[]])]

All the pre-compilation mappings can be found in the code.

I hope this is helpful for somebody trying to build their own JSFuck variant or understanding how this variant works... 😅

[kamil-kielczewski]

@baboures thanks for your effort. However may be there is a way to avoid deprecated methods (italics) in shorter way than in js fuck https://stackoverflow.com/a/63850312/860099 (which has ~16kb)

[baboures]

To keep backward compatibility with older code, I don't think browsers will remove the String#italics in a near future.

@kamil-kielczewski If the decoding is 16k characters long, what is the benefit of your solution over using italics()?

[kamil-kielczewski]

@baboures - safety - if in future they remove this deprecated method - jsf will stop works (that 16kb alternative solve this - however I hope there is better solution)

[baboures]

@kamil-kielczewski do you consider solutions using escape/unescape? Those functions are not strictly deprecated as per the docs.

[wakfi]

I hope there is better solution

I found an approach using Function('return this')()['btoa']('p+m')[1] to produce letter C. The compiler spits out about 9kb when given that string, but when I found it I did it in ~4kb. Would that be a viable alternative? Or is there some reason for avoiding btoa that I'm missing?

For completeness, my 4.3kb solution

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[kamil-kielczewski]

@wakfi as it was written in this question https://stackoverflow.com/questions/63673610/alternative-way-to-get-c-letter-in-jsfuck - btoa not works on node.js (solution provided there has <1.5kb). @baboures escape/unescape solutions are also discussed in answers in that link

[wakfi]

@wakfi as it was written in this question https://stackoverflow.com/questions/63673610/alternative-way-to-get-c-letter-in-jsfuck - btoa not works on node.js

@kamil-kielczewski btoa is supported in nodejs under legacy stability level support. Apparently it was only added (as a global) in nodejs v16 though, I hadn't realized that. It was added (and will be kept) as a measure to improve interoperability between browser JavaScript and NodeJS JavaScript

[kamil-kielczewski]

@wakfi thank you for that info - I will check it

[sofabeddd-old]

I tried making a version called JSFourk, where instead, you only get the characters []+!. Obviously you can't get as far with it as you can't call methods, but it had some interesting challenges to overcome with it:

In JSFuck you can use parentheses for the order of operations which is very useful. For example if I wanted to get the character f in JSFuck, I could just do this:

(![]+[])[+[]] // f

but without the use of parentheses, it adds a whole new aspect. The way to get around this is to simply put your expression into an array and select the first item from that array, like this:

[ /* expression */ ][+[]]

so the letter f in JSFourk would be this:

[![]+[]][+[]][+[]] // f