Why Senior Developers Use Maps Instead of Objects скачать в хорошем качестве

Why Senior Developers Use Maps Instead of Objects

We all love JavaScript Objects. They are the building blocks of the language. But if you are using them as dictionaries or hash maps to store dynamic data, you are likely hurting your code's performance and safety. In this video, we break down the JavaScript Map data structure. We explore why it was introduced in ES6, how it solves the infamous "Object Key Collision" bug, and why its performance for frequent additions and removals destroys plain Objects. We also cover the specific use cases where you should stick with Objects, and when you should upgrade to a Map. In this video, you will learn: Why Objects convert all keys to strings (and why that's bad). How to use Objects and DOM elements as keys in a Map. The performance difference: .size vs Object.keys().length. Guaranteed iteration order. The ultimate rule of thumb: Map vs Object.