Node.js Tutorial for Beginners - 3 - Basic Concepts Video Lecture | The Complete NodeJS Developer Course - Back-End Programming

all right hostas welcome back to another
node J s tutorial and before we get
started I need to tell you a story
nothing to do with nodejs but I need to
get it out so I was at the grocery store
yesterday and I was checking out in the
cashier she was a pretty cute girl
actually she was like and making small
talk you know this and that and
eventually she asked me what I did for
work and I go I'm a programmer you and
then I realized that I just asked the
cashier what she did for work and then I
realized that I am an idiot and my face
got red and I tried to avoid eye contact
so uh yeah pretty embarrassing again you
know that wasn't like a story into what
I'm gonna teach you right now just
something embarrassing that happened to
me so let's get started now in this
tutorial what I want to do is I want to
cover some basics of JavaScript this
isn't really specific to no js' but
these are some concepts that are really
important and we're gonna come across a
lot in nodejs so again I know this isn't
a JavaScript tutorial but these are
really important to understand right now
so the first piece of information is
this whenever you make objects in nodejs
they're the exact same as JavaScript so
you for example you can have like first
name um
Bucky this person object can also have a
property of last name and I'll set that
equal to Roberts sure you separate these
with a comma and we'll just say
something like age 28 alright so again
what you can do is you can actually call
console.log and just print out this
entire object and what's going to do is
just print out the properties make sure
you have your semicolons in there
nothing new now another thing I want to
point out is this so whenever you're
typing JavaScript it's pretty much just
code that runs in your browser it runs
unless you have like a while loop in
there just completes and it's done
however this code right here
think of it as code that's going to run
on your server so it's a little bit
different any nodejs code is going to
run on your server and it's going to run
continuously so this process is still
going on until we stop it
now if you try to run this again I
already set it up so it says are you
sure you want to run this again because
you already have a process running I set
it up to just reboot it but again think
of it like that
again all this code is going to run on
your server server-side code alright so
now that I've got that taken care of
another thing I want to point out is
this so say that you have a function
called add numbers and you just try to
add two numbers together a and B and of
course this just returns a plus B so in
nodejs console.log ah what to number
seven and three all right
so whenever you have a function you try
to log it out what it's going to do is
it prints out the return data so again
whenever I run this it's going to print
out ten so again any function you print
out
more time it's going to return or it's
going to print out the return data
simple enough so why do I say that well
there's gonna come on let's say that we
have a function call like worthless and
it doesn't take any parameters because
all this function does is nothing at all
so let me just call worthless all right
so this function right here check out
what's happening it doesn't have any
return value and your return statement
so whenever we try to run this and print
it out this function is going to be
equal to undefined so that's another
concept that we're going to come across
a lot any function without an explicit
return statement like this it's always
going to return undefined so you
actually saw that before whenever we
just log something out um like in our
very first Itoro law
well what the heck looks at all right
I'm embarrassing there all right
so uh you know when our very first oral
when we were just printing stuff out on
the screen to test everything out you
saw that that is why now one other thing
I want to show you guys is this what you
can do is you can actually have a
variable and we'll just say print bacon
and you can set a variable equal to an
anonymous function so say that we had a
function and we'll just make a really
simple stupid function and uh what's
this function going to do it just print
something now so console.log um bacon is
healthy don't leave the doctors might as
well capitalize that make this a little
bit more formal alright so we pretty
much have a function that prints
something now and my semicolon right
there in what we're doing is this we're
taking this entire function and we're
setting it equal to the print bacon
variable so now we can just do something
like print bacon and look what's
happening so of course whenever you run
this you know what's going to happen
it's going to print out bacon is healthy
don't believe the doctors whatever but
the point is we really don't need a name
for this function so most of the time
whenever we create functions we have a
name so we can reference them and use
them where you want them obviously
however there really isn't a point to
giving this function a name
so in nodejs we don't need to do that
this is called an anonymous function and
another cool concept is we can actually
take these functions and assign them to
variables just like we would you know
like a number or string or anything like
that and of course why would we want to
do this well one cool thing that we can
do is this whenever we have a function
stored in a variable we can actually use
this and pass them to other functions so
set timeout is a function I'm going to
be talking to you guys about a lot in
the next tour
but check this out we can actually pass
print bacon in there and put like five
thousand or something and again I'm
going to be talking to you guys about
what site set timeout means but it
pretty much means arm call this code in
five seconds so when I run this of
course this print bacon is going to run
first immediately it's going to wait
five seconds and then it's going to call
this printmaking from set timeout so
what am I trying to demonstrate here not
printing crap out on the screen I just
want to show you guys that you can
actually take functions assign them to
variables and the benefit of this is we
can actually use these inside other
functions and you're going to be seeing
that a lot later on so for now thing you
guys for watching don't forget subscribe
and well see you later