Imperative sum function that converts the arguments object to an Array.

es5-arguments-imperative-sum.js

var sum = function () {
  var result = 0;
  var args = Array.prototype.slice.call(arguments); // convert arguments into array
  
  args.forEach(function(number) {
    result = result + number;
  });
  
  return result;
};

sum(1, 2, 3, 4, 5); // => 15