Javascript Absolute Beginner's Guide, Third Edition

Kirupa Chinnathambi has spent most of his life trying to teach others to love web development as much as he does. In 1999, before blogging was even a word, he started posting tutorials on kirupa.com. In the years since then, he has written hundreds of articles, written a few books (none as good as this one, of course!), and recorded a bunch of videos you can find on YouTube. When he isn't writing or talking about web development, he spends his waking hours helping make developers happy and productive as a Product Manager at Google. In his nonwaking hours, he is probably sleeping, joining Meena in running after their daughter Akira, protecting himself from Pixel (aka a T-rex in an unassuming cat's body)…or writing about himself in the third person.  You can find him on Twitter, Facebook, LinkedIn, and the interwebs at large. Just search for his name in your favorite search engine.

• Introduction...................1Parlez-Vous JavaScript? 2Contacting Me/Getting Help...................... 21 Hello, World!... 5What Is JavaScript?....... 7Hello, World!.................. 9Statements, Expressions, and Functions..12  I The Basic Stuff2 Values and Variables..................... 15Using Variables............16More Variable Stuff......183 Functions....... 23What Is a Function?.....26A Simple Function.......26Creating a Function That Takes Arguments...........................30Creating a Function That Returns Data...354 Conditional Statements: if, else, and switch............... 39The If/Else Statement..40Switch Statements.......49Deciding Which to Use..............................555 Looping with for, while, and do…while!...................... 57The for Loop................59The Starting Point........62Some for Loop Examples..........................64The Other Loops.........676 Commenting Your Code…FTW!.... 71What Are Comments?.72Commenting Best Practices......................767 Timers............ 79Delaying with setTimeout..........................808 Variable Scope.............................. 85Global Scope...............86Local Scope..................88Miscellaneous Scoping Shenanigans.......899 Closures......... 95Functions Within Functions.......................96When the Inner Functions Aren't Self-Contained................10010 Where Should Your Code Live?.. 109Approach #1: All the Code Lives in Your HTML Document...................113Approach #2: The Code Lives in a Separate File................114So, Which Approach to Use?..................11811 Console Logging Basics.............. 123Meet the Console......124Displaying the Console............................126If You Want to Follow Along...................127Console Logging 101..............................128  II It's an Object-Oriented World12 Of Pizza, Types, Primitives, and Objects................... 135Let's First Talk About Pizza.......................136From Pizza to JavaScript!.........................139What Are Objects?....141The Predefined Objects Roaming Around in JavaScript....14213 Arrays.......... 145Creating an Array......146Accessing Array Values............................147Adding Items.............149Removing Items.........151Finding Items.............152Merging Arrays..........152Mapping, Filtering, and Reducing Arrays.............................153The Old School Way.153Modifying Each Array Item with map.....154Getting One Value from an Array of Items...........................157A Short Foray into Functional Programming........................16014 Strings......... 161The Basics...................162String Properties and Methods...............16315 Combining Strings and Variables 173Our Setup...................17416 When Primitives Behave Like Objects....................... 179Strings Aren't the Only Problem.............180Let's Pick on Strings Anyway...................180Why This Matters.......18217 Numbers...... 185Using a Number........186Operators...................187Incrementing and Decrementing............188Hexadecimal and Octal Values...............190Special Values—Infinity and NaN...........190The Math Object.......191Random Numbers.....19618 Getters and Setters.................... 201A Tale of Two Properties..........................202Meet Getters and Setters........................20519 A Deeper Look at Objects.......... 211Meet the Object........212Creating Custom Objects........................222The this Keyword.......22620 Using Classes.............................. 231The Class Syntax and Object Creation..232Extending Objects.....24021 Extending Built-in Objects.......... 247Say Hello to prototype Again, Sort Of!..249Using a Subclassing Approach................253Extending Built-in Objects Is Controversial................25522 Arrow Functions......................... 259What Are Arrow Functions?.....................260Putting It All Together..............................26323 Making Sense of this and More.. 265The this Keyword 101..............................26624 Booleans and the Stricter === and !== Operators... 277The Boolean Object..278The Boolean Function..............................278Strict Equality and Inequality Operators28125 Null and Undefined.................... 283Null..............................284Undefined...................28426 All About JSON (JavaScript Object Notation).......... 287What Is JSON?...........288Looking Inside a JSON Object...............292Reading JSON Data..297Writing JSON Data?..300  III Working with the DOM27 JS, the Browser, and the DOM... 303What HTML, CSS, and JavaScript Do....304HTML Defines the Structure....................304Prettify My World, CSS!...........................306It's JavaScript Time!...307Meet the Document Object Model........30928 Finding Elements in the DOM.... 315Meet the querySelector Family...............316It Really Is the CSS Selector Syntax........31829 Modifying DOM Elements.......... 321DOM Elements Are Objects, Sort Of!....322Let's Actually Modify DOM Elements.....32430 Styling Our Content................... 337Why Would We Set Styles Using JavaScript?..............338A Tale of Two Styling Approaches..........33831 Using CSS Custom Properties.... 345What Are CSS Custom Properties/Variables?................346Setting Complex Values Easily................34832 Traversing the DOM................... 353Finding Your Way Around........................354Putting It All Together..............................35833 Creating and Removing DOM Elements.................... 363Creating Elements.....364Removing Elements..372Cloning Elements......37434 Quickly Adding Many Elements into the DOM......... 381General Approach.....383Getting Started..........38435 In-Browser Developer Tools........ 397Meet the Developer Tools.......................398  IV Dealing with Events36 Events.......... 417What Are Events?......418Events and JavaScript..............................420A Simple Example.....423The Event Arguments and the Event Type.............42637 Event Bubbling and Capturing... 429Event Goes Down, Event Goes Up........430Meet the Phases........434Who Cares?................437Event, Interrupted.....43838 Mouse Events............................. 443Meet the Mouse Events...........................444The MouseEvent Properties....................451Dealing with the Mouse Wheel..............45439 Keyboard Events........................ 457Meet the Keyboard Events......................458Using These Events...459The Keyboard Event Properties..............460Some Examples.........46140 Page Load Events and Other Stuff............................ 467The Things That Happen During Page Load..........468The DOMContentLoaded and load Events................471Scripts and Their Location in the DOM.473Script Elements: async and defer...........47741 Loading Script Files Dynamically 481The Basic Technique.482Running Our Dynamically Loaded Script First............486Running Dependent Code After Our Script File Has Loaded........48842 Handling Events for Multiple Elements..................... 491How to Do All This....493  V Totally Useful Topics that Only Make Sense Now43 Using Emojis in HTML, CSS, and JavaScript.............. 501What Are Emojis Exactly?........................502Emojis in HTML..........50344 Making HTTP/Web Requests in JavaScript................ 511The Example..............513Meet Fetch.................514Meet XMLHttpRequest............................52045 Accessing the Webcam............... 529The Example..............530Overview of How This Works..................531Adding the Code.......532Examining the Code.53546 Array and Object Destructuring. 539Destructuring Examples...........................54147 Storing Data Using Web Storage.............................. 549How Web Storage Works........................550Getting Your Code On.............................55248 Variable and Function Hoisting.. 559JavaScript and Compiler Behavior.........56049 Working with Sets...................... 565Creating a Set, Part I.566Adding Items to a Set..............................567How Checking for Duplicates Works......567Creating a Set, Part 2569Checking the Size of Our Set..................570Deleting Items from a Set.......................571Checking If an Item Exists.......................572Looping Through Items in a Set.............572Entries, Keys, and Values.........................57350 Conclusion... 577Glossary............................ 581  9780137959167, TOC, 10/13/2022