Project Euler 12 JavaScript Solution

projectEuler12.js

var x = 0, y = 1;

while (factors(x).length <= 500) {
	x += y;
  	y++;
}

console.log(x);

function factors(n) {
  let arr = [], i = 1, max = n;

  while (i < max) {
    if (n % i === 0) {
      arr.push(i); // i is a factor, pass it the array;

      let k = n / i; // k is also a factor 
      if (i !== k) {
        arr.push(k); // only push k if it's not the current i
      }
      max = k;
    }

    i++;
  }  

  return arr.sort((a, b) => a - b);
}

Great solution to cut max down each time through the loop. I had a solution that worked with smaller numbers, but couldn't produce the answer to the PE question. I let the code run for two hours. I plugged your factors function in, and it found the answer instantly.