项目初始化与结构

A well-structured project is the foundation of a solid SaaS — easier to read, maintain, and scale. This lesson sets up your environment and organizes your files.

Your development environment is where you write, test, and run code: a code editor like VS Code, a terminal, and the runtime for your language.

Node.js runs JavaScript outside the browser — a popular backend choice. It ships with npm, the package manager for installing and sharing libraries.

Start a project with npm init in your project directory. It asks a few questions and creates a package.json — add -y to accept the defaults.

package.json is the heart of a Node project: name, version, entry point, custom scripts, and the dependencies your app needs to run.

A consistent directory structure keeps a project legible. A common top level: src/ for code, public/ for assets, config/, tests/, and docs/.

Inside src/, separate concerns: controllers handle requests, services hold business logic, models map data, and routes define endpoints.

The entry point — set by main in package.json, often src/index.js — is where execution begins. This snippet just boots a simple app.

Keep config out of code. Use environment variables (a .env file) for secrets and per-environment settings — and never commit sensitive keys to version control.

Recap: you set up Node.js and npm, learned the role of package.json, explored a maintainable directory structure, and saw how to handle config safely.