Atom - i - Index Of

Characters: i

Tags: array , number

Arity: dyadic

This atom is dyadic, which means it takes two arguments.


Find the first index of y in list x, or 0 if the element is not present.


Automatically casts the left argument to a singleton list if needed. This takes the element on the right and the list on the left, which is opposite of e (Occurs). If you want to check if an element exists in a list and want the list on the left, consider using this instead of e - even though it returns the index and not a boolean value, since Jelly is 1-indexed, 0, the value returned if the element is not found, is the only falsy output, and thus indicates if the element is in the list.