What do you learn about the nodejs development environment?

Node.js Development Environment Study Notes: From Installation to Development Practice

Node.js is a JavaScript running environment based on the Chrome V8 engine. It can be used to easily develop code and run JavaScript applications, including server-side ones. Web application. Before starting Node.js development, you must first prepare the development environment. In this article, we will introduce how to prepare a Node.js development environment and introduce some basic development practices.

1. Install Node.js

First of all, to develop Node.js, you need to install Node.js first. You can download and install the latest version of Node.js from the Node.js official website. During installation, you can select default settings.

2. Install IDE

Choosing a suitable IDE can greatly improve development efficiency. Commonly used IDEs include: Visual Studio Code, WebStorm, Sublime Text, etc. You can choose according to your own preferences and needs. In this article, we choose Visual Studio Code (hereinafter referred to as VS Code) as the development tool.

3. Create a Node.js project

Open an empty folder in VS Code, you can open the terminal through [Terminal]-[New Terminal] on the menu bar . In the terminal, enter the following command to create a simple Node.js project:

mkdir my-node-project
cd my-node-project
npm init

After executing this command, some prompts will appear. You can answer the corresponding questions to create a package.json file. This file contains Basic information about the project, such as name, version, and dependencies. The dependencies field is used to describe the project's dependencies. Node.js will use this field to automatically download and install the required modules.

4. Installing modules

You can use the npm command to install modules. Enter the root directory of the project in the terminal and execute the following command to install the Express module:

npm install express

5. Create an Express application

In order to better understand Node.js For development practice, we can create a simple Express application. In the terminal of VS Code, enter the following command to create an app.js file:

touch app.js

Enter the following code in app.js:

// 引入 express 并创建一个 express 对象
const express = require('express')
const app = express()

// 定义路由
app.get('/', (req, res) => {
  res.send('Hello World!')
})

// 监听端口
app.listen(3000, () => {
  console.log('应用程序已启动，访问 http://localhost:3000')
})

The code is explained as follows:

• Line 1: Use require to introduce the express module and initialize to create an express object.
• Lines 4 - 6: Define a route that returns a "Hello World!" string when the user accesses the root path.
• Line 9: Use the listen() method of the express object to listen to port 3000. When the user accesses this port, the defined route is executed.

6. Run the application

There are two ways to run the application: one is to start the program by entering the command line through the terminal, and the other is to start the program in VS Code Use the debugging function. The following is the specific implementation of the two methods.

Method 1: Enter the command through the terminal

In the terminal of VS Code, execute the following command:

node app.js

Then open the browser and visit http://localhost:3000 , you can see the "Hello World!" response.

Method 2: Use the debugging function in VS Code

In the left panel of VS Code, click the debug icon to open the debugging panel. Then, click [Add Configuration] and select Node.js. VS Code creates a .vscode folder in the project root directory and creates a launch.json file within it. In the launch.json file, modify the configuration items as follows:

{
  "version": "0.2.0",
  "configurations": [
    {
      "type": "node",
      "request": "launch",
      "name": "Node: Launch Program",
      "program": "${workspaceFolder}/app.js",
      "restart": true,
      "protocol": "inspector"
    }
  ]
}

The code is explained as follows:

• Line 5: Specify the program entry file as app.js.
• Line 6: Set up automatic restart when the program starts.
• Line 7: Specifies the use of the inspector protocol to debug the program in VS Code.

Then, click the [Run] button in the debugging panel to start debugging, visit http://localhost:3000, and you can see the response results in the debugging panel of VS Code.

7. Summary

This article introduces how to prepare the Node.js development environment and introduces some basic development practices. Key steps include:

• Install Node.js
• Install IDE
• Create a Node.js project
• Install modules
• Create an Express application
• Run the application

Finally, I hope this article can help readers quickly get started with the Node.js development environment.

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