How to Get Number of Costumes of a Sprite

There are several methods to find the costume count of a sprite in Scratch.

0th Costume Method

The switch costume to ( v) block accepts both costume names and costume numbers. In the case of costume numbers, the number 0 wraps to the last costume, -1 is the second last costume, and so on.

The number of costumes in a sprite is equal to the costume number of the last costume, leading to the following implementation:

when green flag clicked
switch costume to ((0) + (0))
set [number of costumes v] to (costume [number v])

Code explanation:

1. The script starts with a When Green Flag Clicked block as it only needs to run once, when the project is started.
2. The switch costume block needs to be switched to number 0, so a reporter such as addition can be used to input a 0 into the block. A Join block will not work as it returns a string.
3. The costume number is then stored in a variable for later use.

Loop Method

This method involves looping over every costume until the first costume is found. Each iteration increases a counter. This method is less efficient and more complicated than the first so use is not recommended.

when green flag clicked
switch costume to (costume1 v) // switch to the first costume
set [number of costumes v] to [1]
next costume
repeat until <(costume [number v]) = [1]> // repeat until the first costume is reached again
  next costume
  change [number of costumes v] by (1)
end