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.

else if

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

Course Content

Introduction to JavaScript

Introduction to JavaScript

else if

Now, let's explore a scenario where multiple conditions come into play:


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let a = 11;

if (a > 15) {
  console.log('greater than 15');
}

if (a > 10) {
  console.log('greater than 10');
}

if (a > 5) {
  console.log('greater than 5');
}

if (a > 0) {
  console.log('greater than 0');
}

In this example, the variable a is greater than 10, but other messages like "greater than 5" and "greater than 0" are also being printed. This isn't the desired behavior when you want to execute only one condition. The else statement wouldn't work well here due to multiple conditions.

Introducing else if

The else if construct provides a solution for selecting a specific code block within a series of conditions:

As you can see, the else-if statement is straightforward, with an if statement followed by it:

Let's apply this to our example:


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let a = 11;

if (a > 15) {
  console.log("greater than 15");
} else if (a > 10) {
  console.log("greater than 10");
} else if (a > 5) {
  console.log("greater than 5");
} else if (a > 0) {
  console.log("greater than 0");
}

Now, we've created a sequence of conditions. When at least one if condition becomes true, the chain is interrupted.

Note

This structure is useful when you only need one condition to be satisfied.

Adding else

You can also add an else statement after the condition chain. Let's modify our example:


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let a = -61;

if (a > 15) {
  console.log("greater than 15");
} else if (a > 10) {
  console.log("greater than 10");
} else if (a > 5) {
  console.log("greater than 5");
} else if (a > 0) {
  console.log("greater than 0");
} else {
  console.log("No condition is satisfied");
}

Everything was clear?

Thanks for your feedback!

Section 4. Chapter 3

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