Instructor: Welcome back.
So I hope that you have Node installed
on your computer at this point.
And so, let's now actually go ahead
and use Node for the very first time.
And to get started with the section,
please go into the course starter files
and copy this folder to your working directory, okay?
Now, if you didn't download the course files yet,
please go to the GitHub repository,
that is linked all over the course,
and you will find all the files that you need in there.
Then after that, go ahead and open up
the folder in your code editor.
And I'm using VS Code here.
And I actually already loaded it up.
So here is this Node Farm folder.
Now in this video, we will actually
not yet start with the project.
But instead, we're gonna interact with Node
using the command line.
And for that, I'm gonna use the built-in terminal
that VS Code has, hitting control back take for that.
So this command that you see here, actually.
Or you can go to View and Terminal.
Now if you prefer to use another application
for the terminal, that's fine as well
but throughout this course,
I'm always going to use the terminal
that is built in right into VS Code
so that we don't have to jump around
between different windows so much.
Now, to start writing some Node code here in the console,
all we have to do is to write node,
given that you have Node.js installed on your computer
and then, just hit enter.
And this will then open up the Node REPL,
which stands for read-eval-print loop.
So basically here, we can write JavaScript code
just like in a normal terminal.
For example, we can define variables.
And so, here it is.
So, we just defined the name variable.
And in fact, we can write any JavaScript code
that we like in here, okay?
So, that's because at the end of the day,
Node.js is really just a JavaScript run time,
as we just saw before.
So what else can we do?
Well, any type of expression really, will work.
Let's just do some math here, for example.
Okay so any JavaScript will work
and you see that we actually
defined this variable here using const so that is ES6
and that is absolutely no problem in Node.js.
So it supports ES6 in all the newer versions
out of the box without any problem.
That's because we're not running
this JavaScript in any browser,
but it will always run on the server, okay?
So, in fact, we just took JavaScript out of the browser
and we're running it inside of this Node application.
Now if we wanted to exit JS REPL,
so again, this read-eval-print loop, that Node gives us,
there are different ways of doing that.
The first one is to write exit
or actually .exit
and so this exited this Node process, this REPL
and so that started again so that I can
show you some more stuff.
So again, just type Node, hit enter, and that's it.
Oh, and, by the way, if you want to
clear your terminal like I just did,
all you have to do is to hit command K
and that will then clear the command line
and probably on Windows, that is control K, okay?
Anyway, we use the .exit to exit the REPL
but we can also hit control D,
and that's not command, it is really control,
so control D will do the same.
But, let's quickly enter it again
'cause there's some more stuff that I want to show you.
So if you hit tab right now,
maybe you have to tap it twice,
sometimes that happens for some reason,
but anyway, by hitting tab,
you can see all the global variables
that are available in Node.
So you have all the kind of stuff
that we're already used to
like the Array constructor
or the String constructor
or Math
or Number over here,
but then there's also all kinds of stuff
that belongs to Node.
For example, your https and fs or crypto
and these are Node modules
that we're gonna talk more about
a bit later in the section.
But for now, you see that we have all kinds
of global variables that we can access
whenever we want in Node.js, okay?
Also, another nice trick is the underscore variable.
So let me first show you something.
So another calculation for example.
Three times eight gives 24
and now was can use underscore plus six
and so this will give us 30
and so that means that underscore
is basically your previous result.
So we had 24, and so underscore here is 24 now
and 24 plus six makes 30.
So if we now did underscore minus 30,
that will give us zero, right?
And yeah, it did.
Okay, and finally, the tab that you just pressed before,
you can also press that, for example,
on one of these constructor
that we already know like string.
So String. and now by adding tab,
you can see all the methods or properties
that are available to us.
Again, sometimes you have to hit it twice
but then here we are.
So we have, for example, length or hasOwnProperty,
and all these kinds of methods here
that we know already, right?
And now, to exit the REPL,
remember all you have to do is hit control D.
Okay, then command K to clear the console,
and that's it.
So that's all I wanted to show you
in this very, very first video.
So basically that we can write JavaScript now
outside of the browser using Node.js like this.