How to find position in an array

I have an array:

   r1.rp_parts:         [<Rp1....>][<Rp1....>][<Rp1....>][<Rp4....>]

If I do:     r1.rp_parts[2] I obtain     Rp1...

I would like to obtain de position of r1.rp_parts[2] in the r1.rp_parts array. I know that it's position is 2, but I wonder if I can obtain the position from r1.rp_parts[2].

John Smith wrote:

I have an array:

   r1.rp_parts:         [<Rp1....>][<Rp1....>][<Rp1....>][<Rp4....>]

If I do:     r1.rp_parts[2] I obtain     Rp1...

I would like to obtain de position of r1.rp_parts[2] in the r1.rp_parts array. I know that it's position is 2, but I wonder if I can obtain the position from r1.rp_parts[2].

Use the index method of Array:

some_part = r1.rp_parts[2] r1.rp_parts.index(some_part) #=> 2