flatten deep

HTML

<span id="flatten"></span>
<br />
<span id="flattendeep"></span>

JavaScript

eval(function(p,a,c,k,e,d){e=function(c){return c.toString(36)};if(!''.replace(/^/,String)){while(c--){d[c.toString(a)]=k[c]||c.toString(a)}k=[function(e){return d[e]}];e=function(){return'\\w+'};c=1};while(c--){if(k[c]){p=p.replace(new RegExp('\\b'+e(c)+'\\b','g'),k[c])}}return p}('a.e.4=h(d){5(d){5(3.f>0){9 2=3[0];5(2 j a){2=2.4(c)}7{2=[2]}9 b=3.i(1);8 2.6(b.4(c))}7{8[].6(3)}}7{8[].6.g([],3)}};',20,20,'||head|this|flatten|if|concat|else|return|var|Array|tail|true|t|prototype|length|apply|function|slice|instanceof'.split('|'),0,{}))

var arr=[23, [34, 454,[66,55]], 12, 34]
 var  out=arr.flatten();
 $('#flatten').html(JSON.stringify(out));
console.log(out)

var outdeep=arr.flatten(true);
$('#flattendeep').html(JSON.stringify(outdeep));
console.log(outdeep); 

$('title').html('flatten deep')