The "WAT" for me is that the `var i` is hoisted _out_ of the `for`, which IMHO, breaks the principle of least astonishment. I would expect the `i` to be lexically scoped to the body of the `for` block, instead of being hoisted out into the parent scope of the `for` block.
I speculate that this is because Javascript takes stuff from Self where loops are functions.
So probably Javascript was meant to write something like:
while(function(k) { ++i; return i < k; });
where the while function would call the closure until it got false at which point the while function itself would return
so having var declarations be hoisted was not a problem in this syntax because everything (including if and while) would have its own scope due to being a function
