Here is some list of Ruby Array operations and examples.

I’m just pasting here some cool examples for lates Ruby I use. Pls check full list of Array features for your Ruby version

detect Same element in two Ruby arrays

Ruby & method docs

['a', 'b', 'c', 'd', 'e'] & ['a', 'c']
# => ["a", "c"]

['a', 'c']   &  ['a', 'b', 'c', 'd', 'e']
# => ["a", "c"]

['a', 'b', 'c', 'd', 'e'].&(['a', 'c']) will also work

Symbols and strings are not the same!

['a', 'b', :c, :d, :e] & ['a', 'c', :e]
# => ["a", :e]

['a', 'c', :e] & ['a', 'b', :c, :d, :e]
# => ["a", :e]

different element in two Ruby arrays

Ruby difference method docs

['a', 'b', 'c', 'd', 'e'].difference ['a', 'c']
# => ["b", "d", "e"]


['a', 'c'].difference  ['a', 'b', 'c', 'd', 'e']
#  => []

string and symbols:

['a', 'b', :c, :d, :e].difference ['a', 'c', :e]
# => ["b", :c, :d]


['a', 'c', :e].difference ['a', 'b', :c, :d, :e]
 => ["c"]