Finding the median of an array

median_array.rb

#median([1,2,3])      # => 2
#median([4.5, 0, -1]) # => 0
#median([-100, 100])  # => 0.0

def median(array)
  if array.length.odd?
    array.fetch(array.length / 2)
  elsif array.length.even?
    (array.fetch(array.length / 2 -1) + array.fetch(array.length / 2)) / 2.0
  end
end