Finding the sum of an arithmetic progression using a loop is terrifying

This is as simple as it gets

s is not declared in the while loop.

I'm confused. How does the return keyword have access to the s variable if the s variable is locally scoped to the while statements code block?

and now?

Nice solution, did not think about using while loop!

I got 0 for finishing it in PHP. It deserves a 8kyu in PHP and even that is too much

I used this to test

var arr1 = [ [ 1, 2, 3, 4, 5 ],
  [ 6, 7, 8, 9, 10 ],
  [ 11, 12, 13, 14, 15 ],
  [ 16, 17, 18, 19, 20 ],
  [ 21, 22, 23, 24, 25 ] ]

Test.assertSimilar(snail(arr1), [1, 2, 3, 4, 5, 10, 15, 20, 25, 24, 23, 22, 21, 16, 11, 6, 7, 8, 9, 14, 19, 18, 17, 12, 13], 'Hmm')

Why num % i is NaN? It can't be compared with 0

what a genius!

out of my league :(