Immutability is a core principle in functional programming, and has lots to offer to object-oriented programs as well. In this article, I will show what exactly immutability is all about, how to use this concept in JavaScript, and why it’s useful. What is Immutability? The text-book definition of mutability is liable or subject to change or alteration. In programming, we use the word to mean objec
![Immutability in JavaScript — SitePoint](https://cdn-ak-scissors.b.st-hatena.com/image/square/26e92c2ab218940101f2567d3b0c5ad322d10307/height=288;version=1;width=512/https%3A%2F%2Fwww.sitepoint.com%2Fwp-content%2Fthemes%2Fsitepoint%2Fassets%2Fimages%2Ficon.javascript.png)