Belajar NodeJS | 6. NodeJS Module System

Summary

In this video, Sadiqah Galih explains the foundational concepts of the Node.js module system, which allows for organizing and reusing code. She introduces three types of modules: core modules (built-in), local modules (custom-created), and third-party modules (installed via NPM). Through practical examples, viewers learn how to export and import functions, variables, and objects across different files using `module.exports` and `require()`. The tutorial emphasizes best practices, including handling module paths and using objects for multiple exports, and sets the stage for more advanced Node.js topics in upcoming videos.

Takeaways

• 😀 Node.js treats each file as a separate module, allowing for code reuse through exports and imports.
• 😀 Modules in programming are collections of reusable code with a defined interface, allowing different parts of a program to interact with them.
• 😀 In Node.js, modules can be categorized into three types: core modules, local modules, and third-party modules (via NPM).
• 😀 Core modules in Node.js come built-in, such as the file system or network modules, and can be used directly with a simple require statement.
• 😀 Local modules are created by the user within their own project, and can be imported by exporting from one file and requiring it in another.
• 😀 Third-party modules are installed through the Node.js package manager (NPM) and can be used similarly to core modules once installed.
• 😀 When using the `require()` function in Node.js, the system first looks for core modules, then local modules, and finally third-party modules in the `node_modules` directory.
• 😀 Files in Node.js are isolated; one module cannot directly access variables or functions from another module unless they are explicitly exported and imported.
• 😀 It is possible to export multiple elements (like functions, variables, or objects) from a single module, using an object to group them together.
• 😀 To export multiple functions or objects from a Node.js module, you can use `module.exports` to assign an object containing all properties and methods, simplifying imports in other files.

Q & A

What is the main topic of the video?

The video focuses on explaining the concept of the Node.js module system, including how modules are created, exported, and imported in Node.js.

What is a module in programming?

In programming, a module is a collection of code that can be reused. It is typically designed to provide a defined interface for its functionality, which can be accessed by other parts of the program.

What is the specific definition of a module in Node.js?

In Node.js, a module is a functionality, either simple or complex, stored within a JavaScript file. This module can be reused within the application by importing it into other files using the `require` statement.

How does Node.js handle modules differently from traditional JavaScript in the browser?

Unlike JavaScript in the browser, where all variables are in the global scope, Node.js treats each file as a separate module with its own scope. This means variables and functions defined in one file are not directly accessible in another unless explicitly exported and imported using `require` and `module.exports`.

What are the three types of modules in Node.js?

The three types of modules in Node.js are: 1) Core modules, which are built-in modules like `fs` for file system operations. 2) Local modules, which are custom modules created by the developer. 3) Third-party (NPM) modules, which are external modules available through Node.js' package manager, NPM.

How does Node.js resolve the module when using `require`?

Node.js resolves modules in the following order: it first checks if the module is a core module, then looks for local modules (checking for relative paths), and finally checks the NPM modules by searching in the `node_modules` directory.

How can we export multiple functionalities from a single module in Node.js?

To export multiple functionalities from a single Node.js module, we can assign them as properties of an object. For example, we can export a function, a variable, and an object together by defining them in an exported object.

What is the purpose of the `export` keyword in Node.js?

The `export` keyword in Node.js is used to make functions, variables, or objects available to other files. This allows code in one file to be reused and accessed in another file through the `require` statement.

What is the advantage of using local modules in Node.js?

Using local modules in Node.js helps organize the code into smaller, reusable pieces. This modular approach improves code maintainability and scalability by separating different concerns into different files.

How does Node.js handle third-party modules, and where are they stored?

Node.js handles third-party modules through the NPM (Node Package Manager), where developers can install modules created by others. These modules are stored in the `node_modules` folder within the project directory, and can be imported using the `require` statement.