**Arguments** are function variables that you can use inside function only:

function funcName(a, b) {
  console.log("Arg A =", a);
  console.log("Arg B =", b);
};

funcName(15, 24);

console.log(a);  // it will raise Error

Also, if you name the arguments the same name as the variables outside the function, the function will use the arguments instead of the variables:

let a = 15;

function num(a) {
  console.log("(func) a =", a);
};

num(20);

console.log("(global) a =", a);

> Note
>
> When the function finishes execution, its space disappears (all arguments lose value).

Arguments are received sequentially:

function numSet(a, b, c) {
  console.log([a ** 2, b + 2, c - 10]);
};

numSet(15, 12, 99);

Unfilled arguments will receive the value undefined and will not be displayed in any way, in particular, redundant arguments will not be used in any way.

function numSet(a, b, c) {
  console.log([a, b, c]);
}

numSet(12, 13);
numSet(15, 12, 13, 15);

The function receives literals as arguments. Variables outside the function are not changed. An argument is an independent value inside a function:

let a = 15;

function add(numb) {
  numb += 5;
  console.log("(func) numb =", numb);
};

add(a);

console.log("(global) a =", a);

The `numb` argument changed in the example above, and the global variable `a` remained at `15`.

> Note
>
> This does not work for **arrays** because the array contains a reference to some data. This reference passes to the function (the space pointed to by the reference changes). This will be studied in the OOP in JavaScript course.

First, let's get acquainted with JavaScript and look at its syntax. In this section, you will get a basic familiarity with the JavaScript syntax to make it easier to learn in detail later on.

Now it's time to learn about the data types that JavaScript works with. We'll start by looking at the difference between literals and variables, and then delve into the various data types.

We have become familiar with the various data types. Now, let's learn how to work with them by learning the operations we can perform with each data type.

Next, we will learn how to control the flow of execution. It's a straightforward process: we can tell the interpreter exactly what to do under certain conditions.

Next, we will explore how to shorten code using repetitive looped actions. We will examine the types of loops available in JavaScript and learn how to work with them.

Finally, to be able to write simple programs, we need to learn about functions that can make our lives much easier. We will learn how to create and use our functions.