Learning Node.js Development

Creating the async square function

Inside the utils file, we can get started next to the square method creating a new one called asyncSquare:

module.exports.square = (x) => x * x;module.exports.asyncSquare

It'll take two arguments: the original argument which we called x, and the callback function that'll get called after our 1-second delay:

module.exports.square = (x) => x * x;module.exports.asyncSquare = (x, callback) => {};

Then we can finish up the arrow function (=>) and we can start working on the body of asyncSquare. It'll look pretty similar to the asyncAdd one. We'll call setTimeout passing in a callback and a delay. In this case, the delay will be the same; we'll go with 1 second:

module.exports.square = (x) => x * x;module.exports.asyncSquare ...