Getting all but the first element from Ruby array

When getting all but the first element from an array in Ruby, we have a few options.

Given the following list:

list = [1,2,3,4]

Shift

We could use shift, however it mutates the array. It also doesn’t return the list so we need two lines to write this code:

list.shift
# => 1
rest_of_list = list
# => [2,3,4]

In the past I’ve used slice, but specifying indices or passing the length of an array is ugly and low-level:

rest_of_list = list[1..-1]
# => [2,3,4]
rest_of_list = list.slice(1, list.length)
# => [2,3,4]

list # is not modified
# => [1,2,3,4]

My new favorite is drop which does not mutate and does not require ugly, low-level code:

list.drop(1)
# => [2,3,4]

list # is not modified
# => [1,2,3,4]

An added benefit ofdrop is that it will always return an array, while slice will sometimes return nil

[].slice(1..-1)
# => nil

[].drop(1)
# => []