Beginning API Development with Node.js

Application Modularization

Like most programming languages, Node.js uses modules as a way of organizing code. The module system allows you to organize your code, hide information, and only expose the public interface of a component using module.exports.

Node.js uses the CommonJS specification for its module system:

• Each file is its own module, for instance, in the following example, index.js and math.js are both modules
• Each file has access to the current module definition using the module variable
• The export of the current module is determined by the module.exports variable
• To import a module, use the globally available require function

Let's look at a simple example:

// math.js filefunction add(a, b) {  return a + b;}……module.exports = ...