JavaScript object difference using Underscore

gistfile1.js

var objectA = { a: '1a', b: '1b', c: '1c' };
var objectB = { a: '2a', b: '2b', d: '2d' };

function objectDifference(minuend, subtrahend) {
  var firstIntersection = _.omit(minuend, _.keys(subtrahend)),
      secondIntersection = _.omit(subtrahend, _.keys(minuend));
    
  return _.extend(firstIntersection, secondIntersection);
}

var objectC = objectDifference(objectA, objectB);

console.log(objectC); // {c:"1c", d:"2d"}