ES6moduuleissa

ES6 modules, also known as ECMAScript modules or simply JavaScript modules, represent the official standard module system for JavaScript. Introduced in ECMAScript 2015 (ES6), they provide a way to organize and manage JavaScript code in a structured and reusable manner. Prior to ES6 modules, developers relied on various community-driven solutions like CommonJS (used in Node.js) or AMD.

The core concept of ES6 modules involves two key operations: exporting and importing. Developers can explicitly export variables, functions, classes, or objects from a module using the export keyword. This makes these named exports available for use in other parts of the application. Conversely, other modules can import these exported entities using the import keyword, specifying which specific items they need or importing everything.

There are two primary ways to export: named exports and default exports. Named exports allow multiple items to be exported from a single module, and they are imported using their specific names. Default exports designate a single primary export from a module, which can be given any name when imported. This distinction is important for clarity and organization.

ES6 modules are designed to be static, meaning that dependencies can be analyzed at parse time. This allows for optimizations like tree shaking, where unused code can be eliminated during the build process, leading to smaller bundle sizes. They are also asynchronous by nature, supporting dynamic imports, which enable modules to be loaded on demand, further improving performance. ES6 modules are now widely supported in modern browsers and Node.js environments.