What is Javascript?

For most of the people, they may think JavaScript is nothing but a browser language, yes, but furthermore, it can be a common purpose programming language too.

So how do I use it?

1. run it at a browser

open your browser like firefox or chrome, press F12, you shell see a debug window. Click Console, you will see a terminal-like layout, yes, that's it, you can run basic Javascript codes in it.

2. we do it locally. (Actually writing it at local)

1. you shell know what is npm and what is yarn. Basically, they do the same things. But yarn is a newer tool for managing Javascript packages
2. let’s creat a Javascript project first.

• install npm or yarn by sudo apt install npm or sudo apt install yarn
• go to your terminal, mkdir our_javascript_project, cd our_javascript_project
• use npm init -y or yarn init -y to initialize your project (you will get a file which names package.json, that's the core configuration for your Javascript Project)
• now, let’s create our index.js file with vim index.js, typing following: console.log("hello, world!"), save it

3. import and compile

after downloaded your packages(like yarn or npm would do), if you want to run your JavaScript codes, you have to import your package, and in the end, compile your codes to the native codes that every browser can run. So this time, we have to use a new tool, parcel

• install parcel by this command: sudo yarn global add parcel-bundler (you can google the installation instruction too)
• create a html page which contains <script src="./index.js"></script>
• render this page using parcel index.html
• now open the local serving link, for example, http://localhost:1234, press F12, you'll see the hello, world was printed at your browser console, great!

4. see, what if we want to add a new package to this project, what we should do now?

• just use yarn add your_package_name, that should do it

5. and, what if I want to get a single static website, which can run in any browser without the yarn, parcel tools, what I should do?

• well, try this: parcel build index.html
• after that, you can see a new folder dist has been created in your project folder. Inside it, it's your static website, cheer!

Beyond all of these, is endless packages and their own special usage, like react, vue

• Congratulations! you have learned all you should know to make a JavaScript project!

• I’ll see you soon, don’t forget to support me, I am poor in Money: PayPal