simple object comparison

gistfile1.js

var compare = function(a, b) {
  "use strict";
  // iterate over each key in b
  for (var key in b) {
    // check if the key is present in a
    if (key in a) {
      // make sure a and be are not exact matches
      if (b[key] !== a[key]) {
        c[key] = b[key]; // if not an exact match add to c
      }
    } else {
      c[key] = b[key]; // if the key is not found add it to c
    }
  }
  return c;
};