Iterative and recursive fibonacci methods in Ruby with speed test

Fibonacci.rb

# -- Setup

# - recursive
def recursive_fib(x)
  x < 2 ? x : recursive_fib(x-1) + recursive_fib(x-2)
end

# - iterative
def iterative_fib(num)

  a = 0
  b = 1

  num.times do
    temp = a
    a = b
    b = temp + b
  end

  return a

end

# -- Speed tests
require 'benchmark'
num = 35
Benchmark.bm do |x|
  x.report("recursive_fib") { recursive_fib(num) }
  x.report("iterative_fib")  { iterative_fib(num)  }
end

# - output

#  CL > ruby fibonacci.rb
#
#                    user     system      total       real
#  recursive_fib  1.200000   0.010000   1.210000 (  1.214786)
#  iterative_fib  0.000000   0.000000   0.000000 (  0.000007)
#
#  result => iterative wins
#