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

const

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

const

Another way to define a variable in JavaScript is using the const keyword. The primary difference between let and const is that variables created using const cannot change their values, whereas using the let keyword allows changes to the variable's value.

Let's compare the behavior of variables using let and const. Take a look at the following example where we can change the value of the a variable:


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// A variable changing
let a = 5;
console.log(a); // Print the initial value of `a`

a = 10;
console.log(a); // Print the updated value of `a`

In contrast, let's examine the behavior of the b variable. We will encounter an error: TypeError: Assignment to a constant variable.


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// A constant cannot be changed
const b = 7;
console.log(b); // Print the initial value of `b`

// Attempting to reassign a `const` variable will result in an error
b = 8; // This line will throw an error: "TypeError: Assignment to constant variable."
console.log(b);

Usage

Constants are used as immutable variables. You can define a constant once and use it multiple times.

Constants provide data integrity while allowing for quick refactoring.

Note

Refactoring involves making structural changes to the code, such as modifying values, variable/function names, and more.

For example, consider maxHeight for site elements. You can release a site update by changing the maximum height of elements with just one modification in the code. However, it's important to note that you cannot change the maximum height during runtime, ensuring data integrity.


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const maxHeight = 250;
console.log(maxHeight - 15);
console.log(maxHeight - 12);
console.log(maxHeight - 5);
console.log(maxHeight - 13);
console.log(maxHeight - 22);
console.log(maxHeight - 52);

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Seção 2. Capítulo 3

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