This course has been updated! We now recommend you take the Complete Intro to React, v7 course.

Check out a free preview of the full React.js (with Introduction to Flux Architecture) course:
The "PropTypes and Keys" Lesson is part of the full, React.js (with Introduction to Flux Architecture) course featured in this preview video. Here's what you'd learn in this lesson:

The propTypes property of a React component allows developers to declare the data type of each prop. Custom propTypes can also be created. Ryan gives a propTypes demonstration and also explains why specifying keys are helpful when working with arrays.

Get Unlimited Access Now