multiples-of-3-or-5.js

// If we list all the natural numbers below 10 that are multiples of 3 or 5, we get 3, 5, 6 and 9. The sum of these multiples is 23.
// 
// Finish the solution so that it returns the sum of all the multiples of 3 or 5 below the number passed in.
// 
// Note: If the number is a multiple of both 3 and 5, only count it once. Also, if a number is negative, return 0(for languages that do have them)
// 
// Courtesy of projecteuler.net

function solution(number){
  if (number <= 0) return 0;
  let multiples = [];
  for (let i = 1; i < number; i++) {
    if (!(i % 3) || !(i % 5)) {
      multiples.push(i);
    } 
  }
  return multiples.reduce((acc,num) => {
    return acc + num;
  }, 0);
}

// The previous solution is strange, this is better
function solution2(number){
  if (number <= 0) return 0;
  let sum = 0;
  for (let i = 1; i < number; i++) {
    if (!(i % 3) || !(i % 5)) {
      sum +=i;
    } 
  }
  return sum;
}