ahah génial ^_^

Ma petite version plus courte :
_='' // ''
_++ + '' // "0"
_++ + '' // "1"
_++ + '' // "2"
_++ + '' // "3"
...

_='' // ''
_=_[_]+''// "undefined"
_=!''+'' // "true"
_=!!''+'' // "false"

_=__='' // ''
_=_[_]+''// "undefined"
_[__++] //u
_[__++] //n
_[__++] //d
...

via http://spynaej.eu/links/?qUd-hw
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