returning array without specific elements in ruby

Question

I looked really hard in http://www.ruby-doc.org/core-2.1.2/Array.html but I couldn't find a quick functionality to this behaviour:

arr = [1,2,3,4,5,6]

arr.without(3,6) #=> [1,2,4,5]

I know I can write my own function/monkey-patch ruby/add a class method/write it in a few lines.

Is there a way to do this in a ruby way?

Answer 1

you can use subtraction :

arr - [3,6]

EDIT

if you really wanted you could alias this method

class Array
  alias except - 
end

then you can use:

arr.except [3,6]

Answer 2

This got added in Rails 5 :)

https://github.com/rails/rails/issues/19082

module Enumerable
  def without(*elements)
    reject { |element| element.in?(elements) }
  end
end

it's just aesthetics, but it makes sense for the brain

Answer 3

There is another way using reject. But it is not cleaner than -

arr.reject{|x| [3,6].include? x}