ruby array contains code example

Example 1: ruby array has element

>> ['Cat', 'Dog', 'Bird'].include? 'Dog'
=> true

Example 2: ruby in array

You can just use a set difference (aka minus) to see if one array includes all elements of another

not_included = [1,2,3] - (1..9).to_a
not_included      # => []

not_included = [1,2,3,'A'] - (1..9).to_a
not_included      # => ["A"]