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Javascript Absolute Beginner's Guide, 3rd Edition

Name: Javascript Absolute Beginner's Guide, 3rd Edition
Author: Kirupa Chinnathambi
ISBN: 9780137959211

by Kirupa Chinnathambi

November 2022

Beginner

624 pages

13h 39m

English

Que

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Cover Page
About This eBook
Title Page
Copyright Page
Credits
Contents at a Glance
Reader Services
Table of Contents
About the Author
About the Technical Editor

Dedication
Acknowledgments
We Want to Hear from You!
Introduction
Parlez-Vous JavaScript?Contacting Me/Getting Help
1 Hello, World!
What Is JavaScript?Hello, World!Statements, Expressions, and Functions
I The Basic Stuff
2 Values and Variables
Using VariablesMore Variable Stuff
3 Functions
What Is a Function?A Simple FunctionCreating a Function That Takes ArgumentsCreating a Function That Returns Data
4 Conditional Statements: if, else, and switch
The If/Else StatementSwitch StatementsDeciding Which to Use
5 Looping with for, while, and do…while!
The for LoopThe Starting PointSome for Loop ExamplesThe Other Loops
6 Commenting Your Code…FTW!
What Are Comments?Commenting Best Practices
7 Timers
Delaying with setTimeout
8 Variable Scope
Global ScopeLocal ScopeMiscellaneous Scoping Shenanigans
9 Closures
Functions Within FunctionsWhen the Inner Functions Aren’t Self-Contained
10 Where Should Your Code Live?
Approach #1: All the Code Lives in Your HTML DocumentApproach #2: The Code Lives in a Separate FileSo, Which Approach to Use?
11 Console Logging Basics
Meet the ConsoleDisplaying the ConsoleIf You Want to Follow AlongConsole Logging 101
II It’s an Object-Oriented World
12 Of Pizza, Types, Primitives, and Objects
Let’s First Talk About PizzaFrom Pizza to JavaScript!What Are Objects?The Predefined Objects Roaming Around in JavaScript
13 Arrays
Creating an ArrayAccessing Array ValuesAdding ItemsRemoving ItemsFinding ItemsMerging ArraysMapping, Filtering, and Reducing ArraysThe Old School WayModifying Each Array Item with mapGetting One Value from an Array of ItemsA Short Foray into Functional Programming
14 Strings
The BasicsString Properties and Methods
15 Combining Strings and Variables
Our Setup
16 When Primitives Behave Like Objects
Strings Aren’t the Only ProblemLet’s Pick on Strings AnywayWhy This Matters
17 Numbers
Using a NumberOperatorsIncrementing and DecrementingHexadecimal and Octal ValuesSpecial Values—Infinity and NaNThe Math ObjectRandom Numbers
18 Getters and Setters
A Tale of Two PropertiesMeet Getters and Setters
19 A Deeper Look at Objects
Meet the ObjectCreating Custom ObjectsThe this Keyword
20 Using Classes
The Class Syntax and Object CreationExtending Objects
21 Extending Built-in Objects
Say Hello to prototype Again, Sort Of!Using a Subclassing ApproachExtending Built-in Objects Is Controversial
22 Arrow Functions
What Are Arrow Functions?Putting It All Together
23 Making Sense of this and More
The this Keyword 101
24 Booleans and the Stricter === and !== Operators
The Boolean ObjectThe Boolean FunctionStrict Equality and Inequality Operators
25 Null and Undefined
NullUndefined
26 All About JSON (JavaScript Object Notation)
What Is JSON?Looking Inside a JSON ObjectReading JSON DataWriting JSON Data?
III Working with the DOM
27 JS, the Browser, and the DOM
What HTML, CSS, and JavaScript DoHTML Defines the StructurePrettify My World, CSS!It’s JavaScript Time!Meet the Document Object Model
28 Finding Elements in the DOM
Meet the querySelector FamilyIt Really Is the CSS Selector Syntax
29 Modifying DOM Elements
DOM Elements Are Objects, Sort Of!Let’s Actually Modify DOM Elements
30 Styling Our Content
Why Would We Set Styles Using JavaScript?A Tale of Two Styling Approaches
31 Using CSS Custom Properties
What Are CSS Custom Properties/Variables?Setting Complex Values Easily
32 Traversing the DOM
Finding Your Way AroundPutting It All Together
33 Creating and Removing DOM Elements
Creating ElementsRemoving ElementsCloning Elements
34 Quickly Adding Many Elements into the DOM
General ApproachGetting Started
35 In-Browser Developer Tools
Meet the Developer Tools
IV Dealing with Events
36 Events
What Are Events?Events and JavaScriptA Simple ExampleThe Event Arguments and the Event Type
37 Event Bubbling and Capturing
Event Goes Down, Event Goes UpMeet the PhasesWho Cares?Event, Interrupted
38 Mouse Events
Meet the Mouse EventsThe MouseEvent PropertiesDealing with the Mouse Wheel
39 Keyboard Events
Meet the Keyboard EventsUsing These EventsThe Keyboard Event PropertiesSome Examples
40 Page Load Events and Other Stuff
The Things That Happen During Page LoadThe DOMContentLoaded and load EventsScripts and Their Location in the DOMScript Elements: async and defer
41 Loading Script Files Dynamically
The Basic TechniqueRunning Our Dynamically Loaded Script FirstRunning Dependent Code After Our Script File Has Loaded
42 Handling Events for Multiple Elements
How to Do All This
V Totally Useful Topics that Only Make Sense Now
43 Using Emojis in HTML, CSS, and JavaScript
What Are Emojis Exactly?Emojis in HTML
44 Making HTTP/Web Requests in JavaScript
The ExampleMeet FetchMeet XMLHttpRequest
45 Accessing the Webcam
The ExampleOverview of How This WorksAdding the CodeExamining the Code
46 Array and Object Destructuring
Destructuring Examples
47 Storing Data Using Web Storage
How Web Storage WorksGetting Your Code On
48 Variable and Function Hoisting
JavaScript and Compiler Behavior
49 Working with Sets
Creating a Set, Part IAdding Items to a SetHow Checking for Duplicates WorksCreating a Set, Part 2Checking the Size of Our SetDeleting Items from a SetChecking If an Item ExistsLooping Through Items in a SetEntries, Keys, and Values
50 Conclusion
Glossary
Index
Code Snippets

Content preview from Javascript Absolute Beginner's Guide, 3rd Edition

29 Modifying DOM Elements

In this Chapter

Understand how JavaScript can be used to modify the DOM
Meet the HTML element
Learn how to modify attributes and text values

At this point, you kinda sorta know what the DOM is. You also saw how to find elements using querySelector and querySelectorAll. What’s next is for you to learn how to modify the DOM elements you found:

After all, what’s the fun in having a giant lump of clay (or cookie dough) if we can’t put our hands on it and make a giant mess? Anyway, besides it being fun and all, we will find ourselves modifying the DOM all the time. Whether we are using JavaScript to change some element’s ...

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Javascript Absolute Beginner's Guide, 3rd Edition

by Kirupa Chinnathambi

29

Modifying DOM Elements

Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.