Recursively sum an indefinite number of elements. Use the splat operator to take any number of arguments. When calling this method, be sure to use the splat operator on any arrays that are passed to it or it will not function properly.

sum.rb

def sum ( *args )
  args.length > 1 ? args.pop + sum(*args) : args.pop
end


test_array = [1,2,3,4]

puts sum(1,2) # ==> 3

puts sum(*test_array) # ==> 10
# be sure to use the *splat operator here so it gets passed (1,2,3,4) rather than ( [1,2,3,4] )

puts sum(test_array[-1], test_array[-2])  # ==> 7
# sum the last two elements of an array
# no need to use *splat because you are just accessing individual values in the array

Good point! I tested it and reduce is a lot faster, too!