ArgumentError wrong number of arguments (given 0, expected 1)

Question

I have written a program for codewars that finds the lowest two integers and returns the sum of them:

def sum_two_smallest_numbers(numbers)
  array_lowest = [0, 0]
  main_iterate = 2
  array_lowest[0] = sum_two_smallest_numbers[0]
  array_lowest[1] = sum_two_smallest_numbers[1]
  until main_iterate == sum_two_smallest_numbers.length - 1 #maybe -2, or 0
    if sum_two_smallest_numbers[main_iterate] < array_lowest[0]
      array_lowest[0] = sum_two_smallest_numbers[main_iterate]
      main_iterate += 1
    elsif sum_two_smallest_numbers[main_iterate] < array_lowest[1]
      array_lowest[1] = sum_two_smallest_numbers[main_iterate]
      main_iterate += 1
    else
      main_iterate += 1
    end
  end
  return array_lowest[0] + array_lowest[1]
end

to fulfill tests as follows:

Test.assert_equals(sum_two_smallest_numbers([5, 8, 12, 18, 22]), 13) 
Test.assert_equals(sum_two_smallest_numbers([7, 15, 12, 18, 22]), 19) 
Test.assert_equals(sum_two_smallest_numbers([25, 42, 12, 18, 22]), 30) 

It complains about my first line (this was provided along with an end ), and if I replace numbers with any actual numbers, as in the test cases, it throws this:

syntax error, unexpected tINTEGER, expecting ')'

How can I solve this?

Answer 1

You're recursively calling sum_two_smallest_numbers with no arguments., and it requires an argument. Each time you write sum_two_smallest_numbers , that's a method invocation. When you write sum_two_smallest_numbers[0] , that's a method invocation with no arguments, the [0] would access the 0'th element of the returned value, if the invocation succeeded.

It seems like you might have wanted numbers[0] , sum_two_smallest_numbers[0] .