Introduction to JavaScript

Introduction to JavaScript

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1. Basic Concepts

Our first section will introduce you to JavaScript and explore its syntax. This initial step will give you a fundamental understanding of JavaScript's syntax, setting the stage for more in-depth learning in subsequent sections.

About JavaScript

Challenge: Console Output

Challenge: Single-line Comment

Challenge: Multi-line Comment

2. Variables and Data Types

We'll dive into the essential data types that JavaScript operates with. We'll begin by distinguishing between literals and variables and then explore the diverse range of data types used in JavaScript. This knowledge will form a solid foundation for your journey into JavaScript.

Challenge: Defining the Variable

Data Types Overview

Challenge: Array Operations

3. Basic Operations

We're acquainted with the various data types. It's time to roll up our sleeves and learn how to manipulate them. In this third section, we'll explore the operations that can be performed with each data type, equipping you with practical skills to work effectively with JavaScript's data structures.

Mathematical Operations

Operations with Assignment

Increment and Decrement

Challenge: Variable Operations

Comparison Operations

Logical Operations

Challenge: Comparing Variables

String Concatenation

Challenge: Sentence Building

4. Conditional Statements

Delve into the art of controlling the flow of execution in JavaScript. It's a powerful skill that enables us to instruct the interpreter precisely on how to behave under various conditions. You'll gain the ability to orchestrate your code's behavior.

Challenge: Determining Size

5. Loops

Uncover the code optimization through the use of loops. Loops allow us to streamline our code by performing repetitive actions efficiently. We'll delve into JavaScript's different types of loops and discover how to wield their power effectively.

Challenge: Printing Numbers from 5 to 9

Challenge: Tigers

Challenge: Stopping and Skipping

6. Functions

Unlock the potential of functions as essential tools for crafting simple yet powerful programs. You'll master creating and utilizing functions, empowering you to simplify your coding endeavors and enhance your problem-solving skills.

What is a Function?

Challenge: My Name

Conteúdo do Curso

Introduction to JavaScript

Introduction to JavaScript

Arguments

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


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

funcName(15, 24);

console.log(a);  // This will raise an Error

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


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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, and all arguments lose their values.

Arguments are received sequentially:


              12345
            
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. Redundant arguments will not be used:


              123456
            
function numSet(a, b, c) {
  console.log([a, b, c]);
}

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

The function receives values as arguments. Variables outside the function remain unchanged. An argument is an independent value inside a function:


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let a = 15;

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

add(a);

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

Note
This does not work the same way for arrays because an array contains a reference to some data. This reference is passed to the function, so changes inside the function affect the data outside. This will be studied in the "OOP in JavaScript" course.

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Seção 6. Capítulo 4

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