What is modular JavaScript (ES6 modules)
Modular JavaScript refers to the practice of breaking code into smaller, self-contained files or modules, each responsible for a specific piece of functionality. This approach enhances maintainability, scalability, and code reusability. In ES6 (ECMAScript 2015), JavaScript introduced native module support through ES6 modules, which follow a standardized way to define and import/export code between files.Key Features of ES6 Modules
1. Exporting Code:
We can explicitly define which parts of your module should be made available to other files. This can include variables, functions, classes, or objects.There are two types of exports: named exports and default exports.
- Named Export:
- Default Export:
2. Importing Code:
We can import the functionality exported by other modules into your file using import statements.- Importing Named Exports:
- Importing Default Exports:
3. Modularity:
Each module has its own scope, meaning variables, functions, or classes declared in one module are not accessible from other modules unless explicitly exported.
This isolation helps prevent name collisions and improves code clarity.
4. Static Analysis:
ES6 modules are statically analyzable, meaning the structure of imports and exports can be determined at compile time. This allows for optimizations like tree shaking (removing unused code).
5. Strict Mode:
All ES6 modules run in strict mode by default, enforcing better coding practices and avoiding common JavaScript pitfalls like undeclared variables.
6. Dynamic Imports:
We can dynamically load modules at runtime using the import() function. This is useful for code splitting and lazy loading.
Benefits of ES6 Modules:
- Separation of concerns: By splitting code into modules, you keep each file focused on a single task, improving readability and maintainability.
- Reusability: Modules can be reused across different parts of the application or even in other projects.
- Encapsulation: Modules help encapsulate code, reducing the chances of accidental interference between different parts of the program.
- Tree Shaking: Unused exports can be eliminated by bundlers like Webpack, making the final code smaller.