Tom Henricksen

Javascript.

Basics, Core, and Advanced

Copyright © 2024 by Tom Henricksen

All rights reserved. No part of this publication may be reproduced, stored or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, scanning, or otherwise without written permission from the publisher. It is illegal to copy this book, post it to a website, or distribute it by any other means without permission.

First edition

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Contents

Preface

I. JAVASCRIPT BASICS

1. Starting out with JavaScript

2. JavaScript variables and values

3. JavaScript functions

4. JavaScript Conditionals

5. JavaScript loops

6. JavaScript Variable Scope

7. JavaScript Closures

II. CORE JAVASCRIPT

8. JavaScript Objects

9. JavaScript Arrays

10. JavaScript Type Conversion and Coercion

11. JavaScript Strings

12. JavaScript Numbers

13. JavaScript Arrow Function

14. JavaScript Strict Equality and Inequality

15. JavaScript Object Notation

16. JavaScript spread and Rest operator

III. PART THREE

17. JavaScript Promise.all()

18. Execution Context and Call Stack

19. Scope and Scope Chain

20. JavaScript Hoisting and TDZ

21. JavaScript Maps

22. JavaScript Sets

23. JavaScript Call, Bind, and Apply

24. DOM

About the Author

Preface

The first part focuses on JavaScript basics. Covering topics like variables, functions, and conditionals. We also cover loops and closures too.

Then in part two, we cover the core of JavaScript. Objects, Arrays, Type Conversion, Strings, and Numbers. Also, we review arrow functions that can be confusing syntax. The spread and rest operators are powerful to use.

The third part gets to the advanced topics. For instance, the execution context and call stack are important to understand. Similarly, variable scope and the scope chain can help you know when you can and can’t use a variable.

Overall, this book gives you are clear picture of the strength of JavaScript. It has evolved quite a bit over the many years of use. Starting quite small and growing into a more complete language.

I

JavaScript Basics

In part three, we start with the basics of JavaScript. We code some fundamental aspects to help you understand how to get around.

1

Starting out with JavaScript

I have a confession. JavaScript and I started badly. My first foray was for form validation. I would cuss about its existence.

As luck would have after being reintroduced to it I began to respect it. Over the years it has grown into a powerful language.

JavaScript

With its humble beginnings, JavaScript has evolved into a modern programming language. From the browser to the server it can handle almost everything. Node.js gives it a powerful framework on the server side.

Mozilla created it and here is how they define it. JavaScript is a lightweight interpreted programming language with first-class functions. That is a mouthful!

Code

Let’s look at some basic code. It is an HTML file displaying some JavaScript. Save this code to your local machine.

   

    alert(JavaScript is working!)

Test 1

Test 2

    Regular text

When we run this we will see this.

JavaScript alert message

Once you click ok you will see this.

HTML Screen-shot

Statement

The statement is the basic instruction for JavaScript. We can