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JavaScript from Beginner to Professional

You're reading from   JavaScript from Beginner to Professional Learn JavaScript quickly by building fun, interactive, and dynamic web apps, games, and pages

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Product type Paperback
Published in Dec 2021
Publisher Packt
ISBN-13 9781800562523
Length 546 pages
Edition 1st Edition
Languages
Tools
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Authors (4):
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Codestars By Rob Percival Codestars By Rob Percival
Author Profile Icon Codestars By Rob Percival
Codestars By Rob Percival
Laurence Svekis Laurence Svekis
Author Profile Icon Laurence Svekis
Laurence Svekis
Maaike van Putten Maaike van Putten
Author Profile Icon Maaike van Putten
Maaike van Putten
Rob Percival Rob Percival
Author Profile Icon Rob Percival
Rob Percival
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Table of Contents (19) Chapters Close

Preface 1. Getting Started with JavaScript FREE CHAPTER 2. JavaScript Essentials 3. JavaScript Multiple Values 4. Logic Statements 5. Loops 6. Functions 7. Classes 8. Built-In JavaScript Methods 9. The Document Object Model 10. Dynamic Element Manipulation Using the DOM 11. Interactive Content and Event Listeners 12. Intermediate JavaScript 13. Concurrency 14. HTML5, Canvas, and JavaScript 15. Next Steps 16. Other Books You May Enjoy
17. Index
Appendix – Practice Exercise, Project, and Self-Check Quiz Answers

Variables

Variables are the first building block you will be introduced to when learning most languages. Variables are values in your code that can represent different values each time the code runs. Here is an example of two variables in a script:

firstname = "Maaike";
x = 2;

And they can be assigned a new value while the code is running:

firstname = "Edward";
x = 7;

Without variables, a piece of code would do the exact same thing every single time it was run. Even though that could still be helpful in some cases, it can be made much more powerful by working with variables to allow our code to do something different every time we run it.

Declaring variables

The first time you create a variable, you declare it. And you need a special word for that: let, var, or const. We'll discuss the use of these three arguments shortly. The second time you call a variable, you only use the name of the existing variable to assign it a new value...

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