How can I get the element numbers of array?

Hi
If there is an array of props. And I want to know the specific prop’s element number!
I mean, if the player touches one of the props, then prints the prop’s index number. Which number the prop is. Is there a way for this?

exam:
myArray : int = array{1, 2, 3}
I want to know how to → index of 1 (it’d be 0 if success)