JavaScript Expression

Can anyone help me with this JavaScript expression?

+[[+!![]]+[+![]]+[+!![]]+[-~!![]+-~!![]-~!![]]+[-~!![]]+[+![]]+[+!![]]+[-~!![]+-~!![]]]

A friend sent it to me and asked me to copy and paste it in the browser console.

This is the result:

10162014

If anyone could explain this to me or at least point me to right references please. Thanks!

Answer

First break out your code to this: !![] which returns true (!! is to convert to boolean) and now + converts to number so +!![] returns 1.

![] converts to false so +![] returns 0.

~[] returns -1 and ~![] also returns -1.

~!![] returns -2.

Now, -~!![] returns 2 and -~![] returns 1.

So, combining them all returns 10162014.

All about you to know is ~, !, +, & -