# File lib/extensions/array.rb, line 3 def sample(n = nil) #based on code from https://github.com/marcandre/backports size = self.length return self[Kernel.rand(size)] if n.nil? n = n.to_int raise ArgumentError, "negative array size" if n < 0 n = size if n > size result = Array.new(self) n.times do |i| r = i + Kernel.rand(size - i) result[i], result[r] = result[r], result[i] end result[n..size] = [] result end