Eloquent JavaScript

deepEqual.js

// compare all values of two objects
function deepEqual(first, second) {
  if (typeof first === "object" && typeof second === "object") {

    // iterate over properties of both objects
    for (var property in first) {
      var firstProperty = first[property];
      var secondProperty = second[property];

      return deepEqual(firstProperty, secondProperty);
    }
  }
  else if (first !== second) {
    return false;
  }

  return true;
}

var obj = {here: {is: "an"}, object: 2};
console.log(deepEqual(obj, obj));
// → true
console.log(deepEqual(obj, {here: 1, object: 2}));
// → false
console.log(deepEqual(obj, {here: {is: "an"}, object: 2}));
// → true