CommonJS is the most widely used, unofficial spec right now. CommonJS is a specification for implementing modules in Node.js. According to the CommonJS specification, every module needs to be represented by a separate file. CommonJS modules are imported synchronously. This is the reason why browsers do not use CommonJS as a module loader!
Let's see an example of how to create and import modules using CommonJS. First, we will create a file named math.js that represents a module. Here is sample code that will be inside the module:
const sum =(x, y) => x + y;const sub = (x, y) => x - y;const math = { findSum(a, b) { return sum(a,b); }, findSub(a, b){ return sub(a, b); } } exports.math = math; // or module.exports.math = math
