One of the most common error sources: Not understanding what the difference between reference and primitive values is. This video will clear up the confusion. Need more JavaScript Training? Consider my "Accelerated JavaScript Training" course, available for $15: https://www.udemy.com/javascript-bootcamp-2016/?couponCode=YOUTUBE_PROMO Want to take the next step? Dive into ES6 for only $14: https://www.udemy.com/es6-bootcamp-next-generation-javascript/?couponCode=YOUTUBE_PROMOS Stack vs Heap: https://www.quora.com/What-is-the-difference-between-the-stack-and-the-heap Object.assign(): https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/assign Slice(): https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Global_Objects/Array/slice Lodash Clone Deep: https://lodash.com/docs/#cloneDeep Want to become a frontend developer? Consider diving into some of my courses on Udemy: Ionic 2 - The Practical Guide for only $15: https://www.udemy.com/ionic-2-the-practical-guide-to-building-ios-android-apps/?couponCode=GETINTOIT Angular - The Complete Guide for only $15, too: https://www.udemy.com/the-complete-guide-to-angular-2/?couponCode=YOUTUBE_2 Vue.js 2 - The Complete Guide for only $15: https://www.udemy.com/vuejs-2-the-complete-guide/?couponCode=YOUTUBE_VUE Want to get some 1-on-1 coaching with experienced developers? Have a look at Savvy: https://www.savvy.is/?ref=9fee2b (Discount Code 9fee2b) You can follow me on Twitter (@maxedapps), Facebook (https://www.facebook.com/academindchannel/) or visit our Website (https://www.academind.com). See you in the videos!