Let’s add face detection to our React map explorer app using the pico.js JavaScript library ...

JavaScript is also the most popular coding language. According to the 2018 Stack Overflow Developer Survey, JavaScript has been the most used programming language by developers for six years in a row.

While this sounds pretty straightforward, it doesn’t quite telegraph the kind of power you have with first-class functions. If you write JavaScript, you have probably used higher-order functions ...