Page 253 - Scratch Programming Playground

If the cat is moving up, the change y by -1 block makes the
cat look like it’s bumping its head. otherwise, the script behaves
as it did previously, raising the cat so it sits above the ground.
Next, we have to edit the handle ground call in this script.
We’ll add a Boolean condition to determine whether the sprite
is moving up, which is y velocity > 0.

the handle ground y velocity > 0 block sets the moving
up input to true if the y velocity is greater than 0 (that is, if the
sprite is jumping and moving up). If y velocity is not greater
than 0, then the sprite is either falling down or still, causing
the moving up input to be set to false.

MakING aN advaNCed pLatforMer 227