RUBY

ruby array includes

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

# Rails ActiveSupport
'Unicorn'.in?(['Cat', 'Dog', 'Bird'])
# => false

# Via case statement
element = 3
array = [1, 2, 3, 4, 5]
case element
when *array 
  puts 'found in array'
else
  puts 'not found in array'
end

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"]