Introduction to Ruby - Computing Factorials Recursively : An Example of Recursion
# n! = n * (n-1) * (n-2) * .... 1 # Let's use recursion to solve this in Ruby. # A statutory warning: recursion is not the most effective way to solve this problem, specially given its tail-recursive nature
def recursiveFactorial(x) return1if x == 1 return x * recursiveFactorial(x-1) end
# Enter a number puts"Enter a Number" N = gets().to_i # Display the Factorial of the number puts"The Factorial is:" puts recursiveFactorial(N).to_s
=begin Some Sample Outputs *************************
~/work/ruby_tutorials$ ruby recursiveFactorial.rb Enter a Number 10 The Factorial is: 3628800
~/work/ruby_tutorials$ ruby recursiveFactorial.rb Enter a Number 8 The Factorial is: 40320 =end