Determine if one array contains all elements of another array

Question

I need to tell if an array contains all of the elements of another array with duplicates.

[1,2,3].contains_all? [1,2]   #=> true
[1,2,3].contains_all         


        

Answer 1

class Array
  def contains_all? other
    other = other.dup
    each{|e| if i = other.index(e) then other.delete_at(i) end}
    other.empty?
  end
end