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Let's dive into the world of JavaScript

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by starting a fun project
in a new and empty folder.

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Open your preferred IDE
such as Visual Studio Code.

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I have opened WebStorm because that's
my favorite IDE and let's create a new

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file name play.js
the name is entirely up to you.

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Before we start coding,

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let's review some core language features
including variables and functions.

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For now, it is assumed that you have
a basic understanding of variables,

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functions, if statements and loops as
these are essential components

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of JavaScript programming whether you're
using it in the browser or on the server.

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To declare a variable in JavaScript we use

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var keyword and then
the name of the variable.

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So let's create a variable called name
and let's give it the value of Nata.

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Now this name can be used
to output variable's value.

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So if I do this, save this.

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And then try to run this,
I will see the output of Nata.

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We can also create variables of different
data types such as numbers and booleans.

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For example, my age is 26 and I have

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some hobbies. So, I can set this to true.

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If I were to output the values
of these variables, we are going to

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see all of these console log.

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Functions are
declared using function keyword followed

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by the function name such as function

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who is user and we can pass it the name

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and we can pass it an age
and it can return a certain string.

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Let's say, name is - name and age is - age.

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In this example, the function of who is
user accepts two arguments: name and age,

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and it returns a string with the
description of who is the user.

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To call a function, we simply use its name
followed by parentheses

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and then we pass it the arguments that it
needs so that it executes correctly.

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So here we can use the variables that we

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created above and we can console
log the value of this function.

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So if we were to rerun this again,
we would see name is nata and age is 26.

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It's important to note that variables

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declared within a function are local
and cannot be accessed outside

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of the function due to the concept
of scoping in JavaScript.

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However, we can access global
variables within a function.

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So if we were to create a variable here

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let's say we call this

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name age combination and we were to

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do this, if we tried to output

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it here -

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our editor will already be

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telling us that we don't
have access to this.

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However, let's run this and see what

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happens and we get an error saying
name age combination is not defined.

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However, if we were to do the

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same here and we try to console log
name age combination here

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if we were to run this

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we would see

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the name age combination here
because this is a global variable.

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In conclusion, this is just a quick

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overview of the core features you should

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be aware of in JavaScript.

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Variables, functions, arguments,
and scoping are essential components

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of the language,
and mastering these concepts will lay

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a strong foundation for your future
JavaScript programming adventures.

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In the next lecture,
we'll delve into more exciting topics.

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See you in the next video.