Return an average of an array in JavaScript

Question

Looking to receive an array and take and return the average. If it is an empty string return 0. This is the code I have so far.

For some reason I am getting NaN when entered an empty array.



function calculateAverage(numbers) {
  if ((numbers = [])) return 0;
  let total = 0;
  for (let num of numbers) {
    total += num;
  }
  let result = total / numbers.length;
  return result;
}