[thalesmello]

So, if I want get the sum of an array of numbers, the only option is to use recursion or a reduce function? Is there a way to accomplish this using a for loop while sticking to let keywords?

[Skalman]

Perhaps you didn't catch that basically the difference between let and var is that let is block-scoped, while var is function-scoped?

  let result = 0;
  for (let i = 0; i < arr.length; i++) {
    result += arr[i];
  }