Tutorial: Node.js for Beginners

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  • 6 minutes to read

If you're brand new to using Node.js, this guide will help you lot to get started with some nuts.

  • Try using Node.js in Visual Studio Lawmaking
  • Create your offset Node.js spider web app using Express
  • Try using a Node.js module

Prerequisites

  • Installing on Node.js on Windows or on Windows Subsystem for Linux

If y'all are a beginner, trying Node.js for the commencement time, we recommend installing directly on Windows. For more information, see Should I install Node.js on Windows or Windows Subsystem for Linux

Effort NodeJS with Visual Studio Lawmaking

If you take non yet installed Visual Studio Code, render to the prerequisite section above and follow the installation steps linked for Windows or WSL.

  1. Open your command line and create a new directory: mkdir HelloNode, then enter the directory: cd HelloNode

  2. Create a JavaScript file named "app.js" with a variable named "msg" within: echo var msg > app.js

  3. Open the directory and your app.js file in VS Code using the command: lawmaking .

  4. Add together a elementary string variable ("Hello World"), so send the contents of the cord to your panel by entering this in your "app.js" file:

                      var msg = 'Hello Globe'; console.log(msg);

  5. To run your "app.js" file with Node.js. Open up your final correct inside VS Code by selecting View > Terminal (or select Ctrl+`, using the backtick character). If you lot need to change the default terminal, select the dropdown menu and choose Select Default Shell.

  6. In the last, enter: node app.js. You should see the output: "How-do-you-do Earth".

Notation

Detect that when you blazon console in your 'app.js' file, VS Code displays supported options related to the console object for you to choose from using IntelliSense. Try experimenting with Intellisense using other JavaScript objects.

Create your first NodeJS web app using Limited

Limited is a minimal, flexible, and streamlined Node.js framework that makes it easier to develop a web app that tin handle multiple types of requests, like Go, PUT, POST, and DELETE. Express comes with an awarding generator that will automatically create a file architecture for your app.

To create a projection with Express.js:

  1. Open your command line (Command Prompt, Powershell, or whatever you adopt).

  2. Create a new project folder: mkdir ExpressProjects and enter that directory: cd ExpressProjects

  3. Use Express to create a HelloWorld project template: npx express-generator HelloWorld --view=pug

    Note

    We are using the npx command hither to execute the Limited.js Node package without really installing it (or past temporarily installing it depending on how you want to think of it). If you attempt to use the express command or check the version of Express installed using: express --version, you volition receive a response that Express cannot be found. If y'all desire to globally install Express to utilise over and again, utilise: npm install -g express-generator. You can view a list of the packages that have been installed by npm using npm listing. They'll be listed by depth (the number of nested directories deep). Packages that you installed will be at depth 0. That parcel's dependencies will be at depth 1, farther dependencies at depth 2, and then on. To learn more, run into Departure between npx and npm? on StackOverflow.

  4. Examine the files and folders that Limited included by opening the project in VS Code, with: lawmaking .

    The files that Limited generates volition create a web app that uses an compages that tin can appear a little overwhelming at first. You lot'll encounter in your VS Code Explorer window (Ctrl+Shift+E to view) that the following files and folders have been generated:

    • bin. Contains the executable file that starts your app. It fires upwards a server (on port 3000 if no alternative is supplied) and sets up basic error handling.
    • public. Contains all the publicly accessed files, including JavaScript files, CSS stylesheets, font files, images, and any other assets that people need when they connect to your website.
    • routes. Contains all the road handlers for the application. Ii files, index.js and users.js, are automatically generated in this folder to serve as examples of how to separate out your application's route configuration.
    • views. Contains the files used past your template engine. Express is configured to await hither for a matching view when the render method is called. The default template engine is Jade, but Jade has been deprecated in favor of Pug, and so nosotros used the --view flag to change the view (template) engine. Y'all can see the --view flag options, and others, past using limited --help.
    • app.js. The starting betoken of your app. It loads everything and begins serving user requests. It's basically the glue that holds all the parts together.
    • parcel.json. Contains the project description, scripts manager, and app manifest. Its principal purpose is to track your app'south dependencies and their corresponding versions.

  5. You now need to install the dependencies that Express uses in society to build and run your HelloWorld Limited app (the packages used for tasks like running the server, equally defined in the package.json file). Inside VS Lawmaking, open your concluding by selecting View > Terminal (or select Ctrl+`, using the backtick character), be certain that you're still in the 'HelloWorld' project directory. Install the Express package dependencies with:

                      npm install

  6. At this point y'all have the framework set up for a multiple-page spider web app that has access to a big variety of APIs and HTTP utility methods and middleware, making it easier to create a robust API. Showtime the Limited app on a virtual server by entering:

                      npx cross-env DEBUG=HelloWorld:* npm start

    Tip

    The DEBUG=myapp:* part of the command above means you are telling Node.js that you lot want to turn on logging for debugging purposes. Remember to replace 'myapp' with your app proper name. You tin notice your app name in the package.json file under the "name" property. Using npx cross-env sets the DEBUG environs variable in any terminal, only y'all can as well set it with your last specific way. The npm get-go command is telling npm to run the scripts in your bundle.json file.

  7. You can now view the running app by opening a web browser and going to: localhost:3000

    Screenshot of Express app running in a browser

  8. At present that your HelloWorld Limited app is running locally in your browser, endeavour making a alter by opening the 'views' binder in your project directory and selecting the 'alphabetize.pug' file. Once open, change h1= title to h1= "Hello Globe!" and selecting Salvage (Ctrl+Southward). View your change by refreshing the localhost:3000 URL on your web browser.

  9. To end running your Express app, in your terminal, enter: Ctrl+C

Try using a Node.js module

Node.js has tools to help yous develop server-side spider web apps, some built in and many more bachelor via npm. These modules can help with many tasks:

Tool Used for
gm, sharp Image manipulation, including editing, resizing, compression, and then on, directly in your JavaScript code
PDFKit PDF generation
validator.js String validation
imagemin, UglifyJS2 Minification
spritesmith Sprite sheet generation
winston Logging
commander.js Creating command-line applications

Let's apply the built-in OS module to get some data about your computer's operating organization:

  1. In your command line, open the Node.js CLI. You'll come across the > prompt letting you lot know you're using Node.js after inbound: node

  2. To identify the operating arrangement you are currently using (which should return a response letting you know that you're on Windows), enter: bone.platform()

  3. To check your CPU's compages, enter: bone.arch()

  4. To view the CPUs available on your system, enter: os.cpus()

  5. Leave the Node.js CLI by inbound .go out or past selecting Ctrl+C twice.

    Tip

    You lot can utilise the Node.js OS module to do things like check the platform and render a platform-specific variable: Win32/.bat for Windows development, darwin/.sh for Mac/unix, Linux, SunOS, and and so on (for example, var isWin = procedure.platform === "win32";).