This is only a guess, cause what you showed I’m not sure is enough.
(basic description)
But ++i means add 1, then process. so it skips 0.
i++ means process and then add 1.
*Please also use code tags. Using code tags properly *
I figured out why you’re not using the index, you are, just the forum is converting it to italics*,* thus the importance of code tags. 