y is commonly used as a variable to keep track of a game object's vertical position. In 2D games, you should always declare y as a floating point or real data type, as game objects rarely move in increments of integers unless the game has a very high resolution or runs very slowly.
- vspeed - the vertical speed of a game object
- gravity - the acceleration of gravity on a game object.
This page has been recommended for cleanup, integration, etc.