Function examples

functions.js

// function example
// make a sum function that takes an array
// but it assumes the array will contain numbers
function sum(values) {
  if (!(values instanceof Array)) {
    throw new Error('Values must be an array');
  }
  var i = 0;
  var l = values.length;
  var total = 0;
  for (i; i < l - 1; i++) {
    total += values[i];
  }
  return total;
}
// make a function that takes an average of
// an array of values
function average(values) {
  var total = sum(values);
  n = values.length;
  return total/n;
}

// use the function:

var avg = average([1,2,3,4,5,6]);
console.log(avg);