We can get started with modules by defining a module in one file and making the module available for use in another file with Node.js module.exports syntax. Every JavaScript file run in Node has a local module object with an exports property used to define what should be exported from the file.

Below is an example of how to define a module and how to export it using the statement module.exports.

In menu.js we write:

let Menu = {};
Menu.specialty = "Roasted Beet Burger with Mint Sauce";

module.exports = Menu; 

Let’s consider what this code means.

1. let Menu = {}; creates the object that represents the module Menu. The statement contains an uppercase variable named Menu which is set equal to an empty object.
2. Menu.specialty is defined as a property of the Menu module. We add data to the Menu object by setting properties on that object and giving the properties a value.
3. "Roasted Beet Burger with Mint Sauce"; is the value stored in the Menu.specialty property.
4. module.exports = Menu; exports the Menu object as a module. module is a variable that represents the module, and exports exposes the module as an object.

The pattern we use to export modules is thus:

1. Create an object to represent the module.
2. Add properties or methods to the module object.
3. Export the module with module.exports.

Let’s create our first module.