_ is a variable name, [] becomes 0 when converted to an integer, !![] becomes 1. The + “” + means that the integers 1, 0, 0 get converted to a string - “100”, which gets converted back to an integer because it’s in the for loop. And there’s various other horrible conversions going on to make it all work.
Actually, I prefer this one:
for(_=[];_<+!![]+""+[]*[]+[]*[];_++%+(!![]+!![])?[]:console.log(_));
Or this one without the “undefined” when run in a browser console:
for(_=[];_<+!![]+""+[]*[]+[]*[]-!![]-!![];_++%+(!![]+!![])?[]:console.log(_));_+!![]
Wtf people, can somebody explain?
_ is a variable name, [] becomes 0 when converted to an integer, !![] becomes 1. The + “” + means that the integers 1, 0, 0 get converted to a string - “100”, which gets converted back to an integer because it’s in the for loop. And there’s various other horrible conversions going on to make it all work.