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. Find the sum of all the multiples of 3 or 5 below 1000.

gistfile1.js

/*
euler
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.
Find the sum of all the multiples of 3 or 5 below 1000.
*/

//loop through each number until reaching naturalNumberQty 
function sumMultiplesOf3And5(naturalNumberQty){
  sumOfMultiples = 0;
  for (var i = 1 ; i < naturalNumberQty ; i++) {
    //test if i % 5 === 0 || i % 3 === 0 
    //if true then sum to the acumulator
    if( i % 5 === 0 || i % 3 === 0 ){ sumOfMultiples += i }
    
  };
  //return acumulator
  return sumOfMultiples;

}