How to act differently on the first iteration in a Ruby loop?

Question

I always use a counter to check for the first item (i==0) in a loop:

i = 0 my_array.each do |item|   if i==0     # do something with the first item   end   # common stuff   i += 1 end 

Is there a more elegant way to do this (perhaps a method)?

Answer 1

You can do this:

my_array.each_with_index do |item, index|     if index == 0         # do something with the first item     end     # common stuff end 

Try it on ideone.

Answer 2

Using each_with_index, as others have described, would work fine, but for the sake of variety here is another approach.

If you want to do something specific for the first element only and something general for all elements including the first, you could do:

# do something with my_array[0] or my_array.first my_array.each do |e|    # do the same general thing to all elements  end 

But if you want to not do the general thing with the first element you could do:

# do something with my_array[0] or my_array.first my_array.drop(1).each do |e|    # do the same general thing to all elements except the first  end