A few JavaScript quines

quine-examples.js

// Today, I noticed that someone favorited this tweet of mine from 2012:
// https://twitter.com/cowboy/status/232587756486938624
// !function $(){console.log('!'+$+'()')}() #quine

// So I fooled around for a little bit:

// Shortest JavaScript quine?
(function _(){return'('+_+')()'})()

// Have fun with this one!
(function $($_$,_,_$,_$_,$_){return[_=_[$_$](_$[$_++])][_[$_++]][_[$_++]]([][_[$_--]][_[$_++]](_$_,function($$){return _$[$$]||[$_,_$_,_,$_$,$][$_--]},$_++),_[++$_])})('split',',join,call,map',',()\'\\','1821383038303012434430383082',0)

quine-test.js

// Test a quine like so:
a= your_quine_code
a===eval(a) // must be true

// Eg.
a= (function _(){return'('+_+')()'})()
a===eval(a) // true

// Never ending eval...
let x ="let x =%22quinner%22;let y=decodeURI(x).replace(/quinner/, x);alert(y);eval(y);";let y=decodeURI(x).replace(/quinner/, x);alert(y);eval(y);

// Never ending eval...
let x ="let x =%22quinner%22;let y=decodeURI(x).replace(/quinner/, x);alert(y);eval(y);";let y=decodeURI(x).replace(/quinner/, x);alert(y);eval(y);

A quine in programming is a self-replicating code that, when executed, produces retro bowl its own source code as the output.