Hello and welcome to WD201! In this course, we will learn about a JavaScript runtime environment called Node.js. I'm assuming that you've already completed the Web Development 101 course. This means that you're quite familiar with JavaScript, right?
To recap, JavaScript is a Programming Language, that runs on the end user's browser, and allows us to calculate, manipulate and validate data. Where HTML and CSS are languages that give structure and style to web pages, JavaScript improves the user experience of the web page by converting it from a static page into an interactive one.
Now, have you ever wondered, about the static HTML webpages or the forms that you've designed, and how to make them dynamic? How to store that form's data in a database? Or, what if, you want to send a confirmation email to a user who submits the form? This is where the role of server-side programming comes in.
Web browsers communicate with web servers using the Hypertext Transfer Protocol (HTTP). When you click a link on a web page or submit a form, an HTTP request is sent from your browser to the target web server. On the other side, web servers wait for client request messages. These servers process client requests when they arrive, and respond back to the browser with an HTTP response message.
The body of a successful response contains the requested resource (for example a new HTML page, or an image, etc...), which could then be displayed by the browser.
A dynamic website is one where some response content is generated dynamically, only when needed. On a dynamic website, the HTML pages are normally created by fetching data from a database, and then inserting that data into certain placeholders in HTML template.
Most of the code to support a dynamic website must run on the server. Creating this code is known as server-side programming or back-end programming.
Now imagine, what if you could use your JavaScript knowledge to write back-end or server-side logic? This is where the role of Node.js comes in.
Node.js is a runtime environment for writing server-side JavaScript applications. Node.js is open-source and completely free, it's used by thousands of developers around the world. Node is often used to build back-end services that communicate with client-side applications.
Every browser has their own JavaScript engine that converts JavaScript into code that a computer can understand. For example, both Microsoft Edge and Chrome use V8, and Firefox uses SpiderMonkey.
Before Node.js, you could only run JavaScript in the browser. In 2009, Ryan Dahl came up with the idea of executing JavaScript code on the server-side, by using Chrome's v8 engine. Node.js is a platform which is actually built on top of Chrome's JavaScript Runtime environment, which makes it blazing fast when it comes down to the performance.
So, let's get started with the installation.
In this video, I'll show you, how easily you can setup your computer to write Node.js applications. I'm assuming that you're either running macOS, or some variant of Linux, or you're probably using WSL (Ubuntu) inside of Windows.
There are a number of different ways you can install Node.js on your system. However, one of the most popular is nvm. NVM stands for Node Version Manager. It allows us to quickly install and use different versions of Node.js in our computer.
Even if you only need a single version of Node.js right now, we still recommend using nvm. Because in future it will give you the flexibility to switch to other versions, depending on the requirements of your project, with minimal hassle.
So, to install NVM, follow the process I'll show next:
First, open the terminal or command prompt to execute the following command.
COPY_TO_TERMINAL > curl -sL https://raw.githubusercontent.com/nvm-sh/nvm/v0.39.1/install.sh -o install\_nvm.sh
Here we will download the installation script, using curl or wget.
In this URL, v0.39.1 is the latest version of NVM while I'm recording this video. So when you are doing it, make sure you check the latest version from NVM's Github page, and replace it right here in the command.
OPEN_URL (to show how to check latest NVM version) > https://github.com/nvm-sh/nvm
Now, back in the terminal, let's execute it.
Next, let's run the installation script, that we've just downloaded.
COPY_TO_TERMINAL > bash install\_nvm.sh
This script clones the nvm repository into your home directory ~/.nvm and updates your bash profile(~/.bash_profile, ~/.zshrc, ~/.profile, or ~/.bashrc).
In order to check whether the installation has succeeded or not, reopen the terminal and type the following command.
COPY_TO_TERMINAL > command -v nvm
And, it should return nvm.
EXECUTE
Yaay! It's working! This means, we've successfully installed NVM in our system. Next, I'll show you, how to use NVM effectively.
NVM comes with a lot of sub-commands which you can check by running:
nvm --help
GO THROUGH THE MOST USED COMMANDS ONCE, FROM THE OUTPUT >
To see the list of Node.js versions available to install, enter:
nvm ls-remote
GO THROUGH THE OUTPUT >
Now, we will install a stable Node.js version. FYI, for any kind of software, a stable release is a version that has been tested as thoroughly as possible. In case of node, it's marked as LTS, which stands for Long-term Support. Here, support means that throughout the lifetime of a release, there is a commitment to update and maintain the software.
To install a LTS version of Node.Js, just run:
nvm install --lts
The installation process will take some time to complete. Once it's done, check the Node.Js version using:
node --version
SHOW Output: v16.14.2
Ohh that's great! We've successfully installed it.
If you want, you can also install any specific version as well:
nvm install 17
As I said earlier, in future when you will work on other Node.js applications, you may have to install other versions as well. If you would like to list all installed Node.js version, then run:
nvm ls
EXPLAIN Output
To use a specific version in a project, run:
nvm use 17
npm is a package manager for the JavaScript programming language. It consists of a command-line client, also called npm, and an online database of public and private packages. Open-source developers use npm to share and borrow packages.
When you install a node.js version using nvm, npm also gets installed automatically. You can check npm version by:
npm --version
That’s it, your system is totally ready for starting your learning journey with Node.js. See you in the next lesson.