A language made only of brackets, plus and exclamation marks

Question

A colleague of mine sent me a piece of code made only of brackets () [] {}, plus signs and exclamation points.

[][(![]+[])[!+[]+!![]+!![]]+([]+{})[+!![]]+(!![]+[])[+!![]]+(!![]+[])[+[]]] 

and it happens as follows.

It vaguely reminds me of Brainfuck , but I could not find any esoteric language written as follows.

Could you help me understand what kind of language it is?

Answer 1

This link explains very well how this javascript code works: http://patriciopalladino.com/blog/2012/08/09/non-alphanumeric-javascript.html

:
, , - :
[] -
+[] === 0 , 0
!+[] === true false
!+[]+!+[] === 2 true + true. 1, . , .

, ?
[]+{} === "[object Object]" , ({}) , , ([]).
([]+{})[+!+[]] === "o", , ("abc"[1] == "b").

10 , . , :
"undefined" === [][+[]]+[] ( undefined ),
"NaN" === +{}+[] ( ),
"true" === !![]+[],
"false" === ![]+[]

, . , , btoa (btoa base64), ASCII.

- : []["sort"]["constructor"]("OUR_CODE")() , . , Function. . , ()