Sum of an array of integers in Javascript

recursive-version.js

function sumOfIntArray(array) {
  if (!array.length) {
    return 0;
  }
  return array.pop() + sumOfIntArray(array);
}

reduce-version.js

function sumOfIntArray(array) {
  return array.reduce(function(total, current) { return total + current; }, 0);
}

regular-version.js

function sumOfIntArray(array) {
  var sum = 0;
  while (array.length) {
    sum += array.pop();
  }
  return sum;
}