Check out a free preview of the full Building Web Apps (with React, Ampersand, ES6 and Webpack) course:
The "Keys" Lesson is part of the full, Building Web Apps (with React, Ampersand, ES6 and Webpack) course featured in this preview video. Here's what you'd learn in this lesson:
Henrik spends a few minutes talking about how to make the re-rendering of DOM elements more performant. Adding a “key” attribute and assigning it a primary key from the data will help React determine if that element needs to be updated or mutated.