Explaining the differences between typical methods and recursive methods for my blog.

recursion_explanation.rb

# Typical method definition

def multiply_number(integer)
  puts integer * 2
end

# Typical method calls

multiply_number(5) # this would print to the console the result of 5 * 2
multiply_number(23) # this would print to the console the result of 23 * 2

# Recursive method definition

def count_down_from(integer)
  if integer < 1
    puts "This method is all done!"
    return
  end
  puts integer
  count_down_from(integer - 1) # here is the recursive call,
                               # the method calls itself INSIDE it's own definition.
end

# Recursive method call

count_down_from(5)
# The above method call would print to the console the numbers 5,4,3,2, and 1,
# followed by the string "This method is done!"
count_down_from(100) # This call would print to the console numbers from 100 to 1.