Hey there... I just made a snake game, where each "part" of the snake is a glRect with the coordinates: (snake.x,snake.y) where i is the number of the "part". Since the screen is 30 "pieces" wide and 20 high, I will require an array of 600 (struct snake snakes[600]), where the snake struct holds both x and y. What I want to know is if there is a uppersize limit to what size an array can be. If snakes[1000] will work? And is there a better way of handling this? thanks..

In practice, it is not possible to have all 600 tiles of the gameboard filled up with snake at the same time. The player dies long before this happens.
I guess in theory, a very good player could weave the snake into a giant double spiral or other looped shape that covers the whole board, but at this point its not much of a game anymore...
Most Snake games usually have a set limit for the longest the snake ever grows to keep things reasonable.


Also, if you want a more memory effient way of doing things.
... how are you representing your gameboard? because right now your snake is the same size as the whole board... you could combine the snake and board into a single data structure if you wanted

Or, rather than using an array for the snake you could consider a linkedlist