Please for the love of god learn functional programming. this is a primary example of being stuck thinking there is a RIGHT way to do things according to Object

Please for the love of god learn functional programming. this is a primary example of being stuck thinking there is a RIGHT way to do things according to Object oriented design practices. Firstly objects in JavaScript are not classes, they are just your good old dictionary value store, to an JavaScript object it doesn't matter if u put a function or a value under its property, under the hood its just a pointer pointing to a memory location. infact you can dynamically change it! Also if this code is running in the browser you get ZERO security benefits, i can still read your values through the debugger. But it does impart some very significant slow down, especially if you are calling the getter a LOT. With Box.area; it literally has to resolve the BOX variable name and jump 1 pointer. with BOX.getArea(); it has to create a new scope and stack for the function call and there is SO MUCH MORE going on behind the scenes. The right solution here is absolutely to update your area as the width and height change. please learn functional event driven programming if you are going to give advice on javascript. most of the stuff you learned and got tested on in your HS and College courses about how to properly write object oriented code does not apply to javaScript. ESPECIALLY if performance is vital, which it often is since you interact with user input.