Only [] () +! And other symbols are enough to implement almost any Javascript code.

Please test in Firefox

I have read the following example:
Js Code
<Script>
Alert ("hi there ")
</Script>
It is equivalent
<Script>
([] [(! [] + []) [! + [] +! + [] +! + [] + (!! [] + [] [(! [] + []) [+ [] + ([! [] + [] [[]) [+! + [] + [+ [] + (! [] + []) [! + [] +! + [] + (!! [] + []) [+ [] + (!! [] + []) [! + [] +! + [] +! + [] + (!! [] + []) [+! + []) [+! + [] + [+ [] + (!! [] + []) [+! + [] + (!! [] + []) [+ [] [([] [(!) [] + []) [+ [] + ([! [] + [] [[]) [+! + [] + [+ [] + (! [] + []) [! + [] +! + [] + (!! [] + []) [+ [] + (!! [] + []) [! + [] +! + [] +! + [] + (!! [] + []) [+! + [] + []) [! + [] +! + [] +! + [] + (! [] + []) [+! + [] + (! [] + []) [! + [] +! + [] + (! [] + []) [! + [] +! + [] () [(! [] + []) [+! + [] + (! [] + []) [! + [] +! + [] + (!! [] + []) [! + [] +! + [] +! + [] + (!! [] + []) [+! + [] + (!! [] + []) [+ []) ([] [(! [] + []) [! + [] +! + [] +! + [] + (!! [] + [] [(! [] + []) [+ [] + ([! [] + [] [[]) [+! + [] + [+ [] + (! [] + []) [! + [] +! + [] + (!! [] + []) [+ [] + (!! [] + []) [! + [] +! + [] +! + [] + (!! [] + []) [+! + []) [+! + [] + [+ [] + (!! [] + []) [+! + [] + (!! [] + []) [+ [] [([] [(!) [] + []) [+ [] + ([! [] + [] [[]) [+! + [] + [+ [] + (! [] + []) [! + [] +! + [] + (!! [] + []) [+ [] + (!! [] + []) [! + [] +! + [] +! + [] + (!! [] + []) [+! + [] + []) [! + [] +! + [] +! + [] + (! [] + []) [+! + [] + (! [] + []) [! + [] +! + [] + (! [] + []) [! + [] +! + [] () [(! [] + []) [+! + [] + (!! [] + []) [+ [] + (!! [] + [] [(! [] + []) [+ [] + ([! [] + [] [[]) [+! + [] + [+ [] + (! [] + []) [! + [] +! + [] + (!! [] + []) [+ [] + (!! [] + []) [! + [] +! + [] +! + [] + (!! [] + []) [+! + []) [+! + [] + [+ [] + ([] [(! [] + []) [! + [] +! + [] +! + [] + (!! [] + [] [(! [] + []) [+ [] + ([! [] + [] [[]) [+! + [] + [+ [] + (! [] + []) [! + [] +! + [] + (!! [] + []) [+ [] + (!! [] + []) [! + [] +! + [] +! + [] + (!! [] + []) [+! + []) [+! + [] + [+ [] + (!! [] + []) [+! + [] + (!! [] + []) [+ [] [([] [(!) [] + []) [+ [] + ([! [] + [] [[]) [+! + [] + [+ [] + (! [] + []) [! + [] +! + [] + (!! [] + []) [+ [] + (!! [] + []) [! + [] +! + [] +! + [] + (!! [] + []) [+! + [] + []) [! + [] +! + [] +! + [] + (! [] + []) [+! + [] + (! [] + []) [! + [] +! + [] + (! [] + []) [! + [] +! + [] () + []) [! + [] +! + [] (! [] + []) [+! + [] + (+ [! [] + []) [+ []) [+ [] + ([! [] + [] [[]) [+! + [] + [+ [] + (+ [! [] + [] [(! [] + []) [+ [] + ([! [] + [] [[]) [+! + [] + [+ [] + (! [] + []) [! + [] +! + [] + (!! [] + []) [+ [] + (!! [] + []) [! + [] +! + [] +! + [] + (!! [] + []) [+! + []) [+! + [] + [+! + [] + (!! [] + []) [+ [] + [] [(! [] + []) [! + [] +! + [] +! + [] + (!! [] + [] [(! [] + []) [+ [] + ([! [] + [] [[]) [+! + [] + [+ [] + (! [] + []) [! + [] +! + [] + (!! [] + []) [+ [] + (!! [] + []) [! + [] +! + [] +! + [] + (!! [] + []) [+! + []) [+! + [] + [+ [] + (!! [] + []) [+! + [] + (!! [] + []) [+ [] [([] [(!) [] + []) [+ [] + ([! [] + [] [[]) [+! + [] + [+ [] + (! [] + []) [! + [] +! + [] + (!! [] + []) [+ [] + (!! [] + []) [! + [] +! + [] +! + [] + (!! [] + []) [+! + [] + []) [! + [] +! + [] +! + [] + (! [] + []) [+! + [] + (! [] + []) [! + [] +! + [] + (! [] + []) [! + [] +! + [] () [(! [] + []) [+! + [] + (!! [] + []) [+ [] + (!! [] + [] [(! [] + []) [+ [] + ([! [] + [] [[]) [+! + [] + [+ [] + (! [] + []) [! + [] +! + [] + (!! [] + []) [+ [] + (!! [] + []) [! + [] +! + [] +! + [] + (!! [] + []) [+! + []) [+! + [] + [+ [] + ([] [(! [] + []) [! + [] +! + [] +! + [] + (!! [] + [] [(! [] + []) [+ [] + ([! [] + [] [[]) [+! + [] + [+ [] + (! [] + []) [! + [] +! + [] + (!! [] + []) [+ [] + (!! [] + []) [! + [] +! + [] +! + [] + (!! [] + []) [+! + []) [+! + [] + [+ [] + (!! [] + []) [+! + [] + (!! [] + []) [+ [] [([] [(!) [] + []) [+ [] + ([! [] + [] [[]) [+! + [] + [+ [] + (! [] + []) [! + [] +! + [] + (!! [] + []) [+ [] + (!! [] + []) [! + [] +! + [] +! + [] + (!! [] + []) [+! + [] + []) [! + [] +! + [] +! + [] + (! [] + []) [+! + [] + (! [] + []) [! + [] +! + [] + (! [] + []) [! + [] +! + [] () + []) [! + [] +! + [] (! [] + []) [+! + [] + (+ [! [] + []) [+ [] [+ [] + (!! [] + []) [! + [] +! + [] +! + [] + (!! [] + []) [+! + [] + (!! [] + []) [! + [] +! + [] +! + [])
</Scirpt>

Its implementation principle has a code tableCopy codeThe Code is as follows: (NaN + [] ["filter"]) [11] ',
! Window ["atob"] ("If") [0] ',
"(" "). Fontcolor () [12] ',
# Window ["atob"] ("0iN") [1] ',
$ Window ["atob"] ("0iT") [1] ',
% Window ["atob"] ("0iW") [1] ',
& Window ["atob"] ("0ia") [1] ',
'Window ["atob"] ("0if") [1] ',
(False + [] ["filter"]) [20] ',
) (False + [] ["filter"]) [21] ',
* Window ["atob"] ("0ir") [1] ',
+ Window ["atob"] ("0it") [1] ',
, Window ["atob"] ("0iy") [1] ',
-(NaN + window ["Date"] () [31] ',
. Window ["atob"] ("1i4") [1] ',
/(True + ("") ["sub"] () [10] ',
0-9 ignored */,,,,,,,,,,
: Window ["Date"] () [21] ',
; Window ["atob"] ("O0") [0] ',
<("") ["Sub"] () [0] ',
= (""). Fontcolor () [11] ',
> ("") ["Sub"] () [10] ',
? Window ["atob"] ("0j9") [1] ',
@ Window ["atob"] ("00A") [1] ',
A (+ [] + [] ["constructor"]) [10] ',
B (+ [] + (false) ["constructor"]) [10] ',
C window ["atob"] ("00N") [1] ',
D window ["btoa"] (00) [1] ',
E window ["btoa"] (01) [2] ',
F (0 + [] ["filter"] ["constructor"]) [10] ',
G window ["btoa"] ("0f") [1] ',
H window ["btoa"] ("0 t") [1] ',
I ("Infinity") [0] ',
J window ["atob"] ("00r") [1] ',
K window ["btoa"] ("(") [0] ',
L window ["btoa"] ("/") [0] ',
M window ["btoa"] (0) [0] ',
N ("NaN") [0] ',
O window ["btoa"] (8) [0] ',
P window ["btoa"] ("<") [0] ',
Q window ["btoa"] ("a") [1] ',
R window ["atob"] ("01I") [1] ',
S window ["btoa"] ("I") [0] ',
T window ["btoa"] ("N") [0] ',
U window ["atob"] ("01 W") [1] ',
V window ["atob"] ("01a") [1] ',
W (true + window) [12] ',
X window ["atob"] ("01i") [1] ',
Y window ["btoa"] ("a") [0] ',
Z window ["btoa"] ("f") [0] ',
[(Undefined + [] ["filter"]) [33] ',
\ Window ["atob"] ("01y") [1] ',
] (True + [] ["filter"]) [40] ',
^ Window ["atob"] (014) [1] ',
_ Window ["atob"] (018) [1] ',
'Window ["atob"] ("02A") [1] ',
A ("false") [1] ',
B (window + []) [2] ',
C ([] ["filter"] + []) [3] ',
D ("undefined") [2] ',
E ("true") [3] ',
F ("false") [0] ',
G ([] + ("") ["constructor"]) [14] ',
H window ["atob"] ("aN") [0] ',
I ([false] + undefined) [10] ',
J (window + []) [3] ',
K window ["atob"] ("a0") [0] ',
L ("false") [2] ',
M (Number + []) [11] ',
N ("undefined") [1] ',
O (true + [] ["filter"]) [10] ',
P window ["atob"] ("cN") [0] ',
Q window ["atob"] ("cf") [0] ',
R ("true") [1] ',
S ("false") [3] ',
T ("true") [0] ',
U ("undefined") [0] ',
V (0 + [] ["filter"]) [30] ',
W ([] ["sort"] ["call"] () + []) [13] ',
X window ["atob"] ("eN") [0] ',
Y (NaN + [Infinity]) [10] ',
Z window ["atob"] ("et") [0] ',
{(NaN + [] ["filter"]) [21] ',
| Window ["atob"] ("03y") [1] ',
} (NaN + [] ["filter"]) [41] ',
~ Window ["atob"] (234) [1]'

After splicing the string "eval", how can we convert "eval" into eval? The method is
[] ["Sort"] ["call"] () ["eval"]
[] ["Sort"] ["call"] () equals to []. sort. call () is equivalent to window. Therefore, [] ["sort"] ["call"] () ["eval"] is equivalent to window. eval.
Then the system is physically active. Convert the code table to eval ("blah") to execute any code.
Different browsers have different code tables. Chrome and Firefox have different indexes.
In fact, this code table can be extended to Unicode through the toLocal * () 'function family, which is shorter than fromCharCode.
Http://discogscounter.getfreehosting.co.uk/js-noalnum.php? Txt = alert % 28% 22hi + there % 22% 29