book

JavaScript: A Beginner's Guide, Fourth Edition, 4th Edition

Name: JavaScript: A Beginner's Guide, Fourth Edition, 4th Edition
Author: John Pollock
ISBN: 9780071822015

by John Pollock

August 2013

Beginner

528 pages

12h 18m

English

McGraw-Hill

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Cover
Title Page
Copyright Page
About the Author
Contents at a Glance
Contents
Acknowledgments
Introduction
1 Introduction to JavaScript
What You Need to KnowBasic HTML and CSS KnowledgeBasic Text Editor and Web Browser KnowledgeWhich Version?Remember, It’s Not JavaSimilarities to Other LanguagesBeginning with JavaScriptPrototype-BasedClient-SideScripting LanguagePutting It All TogetherOnline ResourcesTry This 1-1: Use JavaScript to Write TextChapter 1 Self Test
2 Placing JavaScript in an HTML File
Using the HTML Script TagsIdentifying the Scripting LanguageCalling External ScriptsSpecifying When the Script Should LoadUsing <noscript></noscript> TagsCreating Your First ScriptWriting a “Hello World” ScriptCreating an HTML Document for the ScriptInserting the Script into the HTML DocumentTry This 2-1: Insert a Script into an HTML DocumentUsing External JavaScript FilesCreating a JavaScript FileCreating the HTML FilesViewing the Pages in Your BrowserTry This 2-2: Call an External Script from an HTML DocumentUsing JavaScript CommentsInserting Comments on One LineAdding Multiple-Line CommentsChapter 2 Self Test

3 Using Variables
Understanding VariablesWhy Variables Are UsefulVariables as Placeholders for Unknown ValuesVariables as Time-SaversVariables as Code ClarifiersDefining Variables for Your ScriptsDeclaring VariablesAssigning Values to VariablesNaming VariablesUnderstanding Data TypesNumberStringBooleanNullUndefinedTry This 3-1: Declare VariablesUsing Variables in ScriptsMaking a Call to a VariableAdding Variables to Text StringsWriting a Page of JavaScriptCreating the FrameworkDefining the VariablesAdding the CommandsModifying the PageTry This 3-2: Create an HTML Page with JavaScriptChapter 3 Self Test
4 Using Functions
What a Function IsWhy Functions Are UsefulStructuring FunctionsDeclaring FunctionsDefining the Code for FunctionsNaming FunctionsAdding Arguments to FunctionsAdding Return Statements to FunctionsCalling Functions in Your ScriptsScript Tags: Head Section or Body SectionCalling a Function from Another FunctionCalling Functions with ArgumentsCalling Functions with Return StatementsOther Ways to Define FunctionsTry This 4-1: Create an HTML Page with FunctionsScope/Context BasicsGlobal ContextFunction ContextTry This 4-2: Write Your Own FunctionsChapter 4 Self Test
5 JavaScript Operators
Understanding the Operator TypesUnderstanding Arithmetic OperatorsThe Addition Operator (+)The Subtraction Operator (–)The Multiplication Operator (*)The Division Operator (/)The Modulus Operator (%)The Increment Operator (++)The Decrement Operator (– –)The Unary Plus Operator (+)The Unary Negation Operator (–)Understanding Assignment OperatorsThe Assignment Operator (=)The Add-and-Assign Operator (+=)The Subtract-and-Assign Operator (–=)The Multiply-and-Assign Operator (*=)The Divide-and-Assign Operator (/=)The Modulus-and-Assign Operator (%=)Try This 5-1: Adjust a Variable ValueUnderstanding Comparison OperatorsThe Is-Equal-To Operator (==)The Is-Not-Equal-To Operator (!=)The Strict Is-Equal-To Operator (===)The Strict Is-Not-Equal-To Operator (!==)The Is-Greater-Than Operator (>)The Is-Less-Than Operator (<)The Is-Greater-Than-or-Equal-To Operator (>=)The Is-Less-Than-or-Equal-To Operator (<=)Understanding Logical OperatorsThe AND Operator (&&)The OR Operator (||)The NOT Operator (!)The Bitwise OperatorsSpecial OperatorsUnderstanding Order of OperationsTry This 5-2: True or False?Chapter 5 Self Test
6 Conditional Statements and Loops
Defining Conditional StatementsWhat Is a Conditional Statement?Why Conditional Statements Are UsefulUsing Conditional StatementsUsing if/else StatementsUsing the switch StatementUsing the Conditional OperatorUser Input from a PromptTry This 6-1: Work with User InputDefining LoopsWhat Is a Loop?Why Loops Are UsefulUsing Loopsforwhiledo whilefor in and for each inUsing break and continueTry This 6-2: Work with for Loops and while LoopsChapter 6 Self Test
7 JavaScript Arrays
What Is an Array?Why Arrays Are UsefulDefining and Accessing ArraysNaming an ArrayDefining an ArrayAccessing an Array’s ElementsUsing the length Property and LoopsChanging Array Values and Changing the LengthTry This 7-1: Use Loops with ArraysArray Properties and MethodsPropertiesMethodsNesting ArraysDefining Nested ArraysLoops and Nested ArraysTry This 7-2: Nested Arrays PracticeChapter 7 Self Test
8 Objects
Defining ObjectsCreating ObjectsNamingSingle ObjectsTry This 8-1: Create a Computer ObjectObject StructuresConstructor FunctionsUsing PrototypesHelpful Statements for ObjectsThe for-in LoopThe with StatementTry This 8-2: Practice with the Combination Constructor/Prototype PatternUnderstanding Predefined JavaScript ObjectsThe Navigator ObjectThe History ObjectChapter 8 Self Test
9 The Document Object
Defining the Document ObjectUsing the Document Object ModelUsing the Properties of the Document ObjectCollectionsThe cookie PropertyThe dir PropertyThe lastModified PropertyThe referrer PropertyThe title PropertyThe URL PropertyThe URLUnencoded PropertyUsing the Methods of the Document ObjectThe get Methods for ElementsThe open() and close() MethodsThe write() and writeln() MethodsUsing DOM NodesDOM Node PropertiesDOM Node MethodsTry This 9-1: Add a DOM Node to the DocumentCreating Dynamic ScriptsStyles in JavaScriptSimple Event HandlingCoding a Dynamic ScriptTry This 9-2: Try Out Property ChangesChapter 9 Self Test
10 Event Handlers
What Is an Event Handler?Why Event Handlers Are UsefulUnderstanding Event Handler Locations and UsesUsing an Event Handler in an HTML ElementUsing an Event Handler in the Script CodeLearning the EventsThe Click EventFocus and Blur EventsThe Load and Unload EventsThe Reset and Submit EventsThe Mouse EventsThe Keyboard EventsTry This 10-1: Focus and BlurOther Ways to Register EventsThe addEventListener() MethodThe attachEvent() MethodThe Event ObjectDOM and Internet Explorer: DOM Level 0 RegistrationUsing event with Modern Event RegistrationProperties and MethodsEvent InformationTry This 10-2: Using addEventListener()Creating Scripts Using Event HandlersShow Hidden ContentChange ContentChapter 10 Self Test
11 Window Object
Window: The Global ObjectUsing the Properties of the Window ObjectThe closed PropertyThe frames PropertyThe innerWidth and innerHeight PropertiesThe length PropertyThe location PropertyThe name PropertyThe opener PropertyThe parent, self, and top PropertiesThe status and defaultStatus PropertiesTry This 11-1: Use the location and innerWidth PropertiesUsing the Methods of the Window ObjectThe alert(), prompt(), and confirm() MethodsThe find() MethodThe home() MethodThe print() MethodThe setInterval() and clearInterval() MethodsThe setTimeout() and clearTimeout() MethodsTry This 11-2: Use the setTimeout() and confirm() MethodsThe Main Window and New WindowsThe Tale of Pop-up WindowsOpening New WindowsClosing New WindowsMoving, Resizing, and Scrolling New WindowsThe resizeBy() and resizeTo() MethodsThe scrollBy() and ScrollTo() MethodsChapter 11 Self Test
12 Math, Number, and Date Objects
Using the Math ObjectWhat Is the Math Object?How the Math Object Is UsefulPropertiesMethodsTry This 12-1: Display a Random Link on a PageUnderstanding the Number ObjectPropertiesMethodsUsing the Date ObjectProperties and MethodsMethods That Get ValuesMethods That Set ValuesOther MethodsHow About Some Date Scripts?Try This 12-2: Create a JavaScript ClockChapter 12 Self Test
13 Handling Strings
Introduction to the String ObjectThe String ObjectThe String LiteralWhat’s the Difference?Using the Properties and Methods of the String ObjectThe length PropertyMethods of the String ObjectTry This 13-1: Use indexOf() to Test an AddressUsing CookiesSetting a CookieReading a CookieTry This 13-2: Remember a NameUsing Regular ExpressionsCreating Regular ExpressionsTesting Strings Against Regular ExpressionsAdding FlagsCreating Powerful PatternsGrouping ExpressionsThe replace(), match(), and search() MethodsMore InformationChapter 13 Self Test
14 JavaScript and Forms
Accessing FormsUsing the forms ArrayUsing Form NamesUsing an IDUsing the Properties and Methods of the Form ObjectPropertiesMethodsEnsuring the Accessibility of FormsUsing Proper Element and Label OrderUsing <label></label> TagsUsing <fieldset></fieldset> TagsNot Assuming Client-Side ScriptingValidationSimple ValidationTechniquesCheck Boxes and Radio ButtonsTry This 14-1: Request a NumberHTML5 and FormsNew ElementsNew Input TypesNew AttributesHTML5 Form ValidationTry This 14-2: Validate a Phone Number with HTML5 or JavaScriptChapter 14 Self Test
15 An Introduction to Advanced Techniques
Working with ImagesRolloversTry This 15-1: A More Accessible RolloverJavaScript and FramesPurpose of FramesAccessing FramesBreaking Out of FramesDebugging ScriptsTypes of ErrorsAlerts and Using the ConsoleUsing a Lint ToolBrowser Developer ToolsJavaScript and AccessibilitySeparate Content from PresentationEnhancing ContentTry This 15-2: Make This Code AccessibleJavaScript SecuritySecurity and Signed ScriptsPage ProtectionAJAX and JSONAJAXJSONChapter 15 Self Test
16 JavaScript Libraries, HTML5, and Harmony
Using jQueryObtaining jQueryGetting Started: document.ready()Using SelectorsAltering ClassesMethods for EffectsFurther ReadingTry This 16-1: Using jQuery to Create EffectsOther JavaScript LibrariesjQuery Mobilephp.jsnode.jsMooToolsThree.jsJavaScript and HTML5The <canvas> ElementDrag and DropTry This 16-2: Drag and DropECMAScript HarmonyThe const and let KeywordsDefault Argument ValuesClassesMore on HarmonyFurther ReadingNeed Help?Chapter 16 Self Test
A Answers to Self Tests
Chapter 1: Introduction to JavaScriptChapter 2: Placing JavaScript in an HTML FileChapter 3: Using VariablesChapter 4: Using FunctionsChapter 5: JavaScript OperatorsChapter 6: Conditional Statements and LoopsChapter 7: JavaScript ArraysChapter 8: ObjectsChapter 9: The Document ObjectChapter 10: Event HandlersChapter 11: Window ObjectChapter 12: Math, Number, and Date ObjectsChapter 13: Handling StringsChapter 14: JavaScript and FormsChapter 15: An Introduction to Advanced TechniquesChapter 16: JavaScript Libraries, HTML5, and Harmony
Index

Content preview from JavaScript: A Beginner's Guide, Fourth Edition, 4th Edition

Chapter 6

Conditional Statements and Loops

Key Skills & Concepts

• Defining Conditional Statements

• Using Conditional Statements

• Defining Loops

• Using Loops

Now that you have seen how the various operators work in JavaScript, this chapter will instruct you in how to put them to good use. This chapter begins by introducing you to conditional statements and why they are useful to you in scripts. Then, you will learn about all the conditional statement blocks and how to use them. After that, you will learn what loops are and learn how to use the various types of loops within your scripts.

Defining Conditional Statements

In order to ...

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JavaScript: A Beginner's Guide, Fifth Edition, 5th Edition

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JavaScript: A Beginner's Guide, Fourth Edition, 4th Edition

by John Pollock

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