You are previewing Professional: JavaScript® for Web Developers, Third Edition.

Professional: JavaScript® for Web Developers, Third Edition

  1. Cover
  2. Contents
  3. Introduction
  4. Chapter 1: What is Javascript?
    1. A Short History
    2. JavaScript Implementations
    3. JavaScript Versions
    4. Summary
  5. Chapter 2: Javascript in Html
    1. The <script> Element
    2. Inline Code versus External Files
    3. Document Modes
    4. The <noscript> Element
    5. Summary
  6. Chapter 3: Language Basics
    1. Syntax
    2. Keywords and Reserved Words
    3. Variables
    4. Data Types
    5. Operators
    6. Statements
    7. Functions
    8. Summary
  7. Chapter 4: Variables, Scope, and Memory
    1. Primitive and Reference Values
    2. Execution Context and Scope
    3. Garbage Collection
    4. Summary
  8. Chapter 5: Reference Types
    1. The Object Type
    2. The Array Type
    3. The Date Type
    4. The RegExp Type
    5. The Function Type
    6. Primitive Wrapper Types
    7. Singleton Built-in Objects
    8. Summary
  9. Chapter 6: Object-Oriented Programming
    1. Understanding Objects
    2. Object Creation
    3. Inheritance
    4. Summary
  10. Chapter 7: Function Expressions
    1. Recursion
    2. Closures
    3. Mimicking Block Scope
    4. Private Variables
    5. Summary
  11. Chapter 8: The Browser Object Model
    1. The window Object
    2. The location Object
    3. The Navigator Object
    4. The screen Object
    5. The history Object
    6. Summary
  12. Chapter 9: Client Detection
    1. Capability Detection
    2. Quirks Detection
    3. User-Agent Detection
    4. Summary
  13. Chapter 10: The Document Object Model
    1. Hierarchy of Nodes
    2. Working with the DOM
    3. Summary
  14. Chapter 11: Dom Extensions
    1. Selectors API
    2. Element Traversal
    3. HTML5
    4. Proprietary Extensions
    5. Summary
  15. Chapter 12: Dom Levels 2 and 3
    1. DOM Changes
    2. Styles
    3. Traversals
    4. Ranges
    5. Summary
  16. Chapter 13: Events
    1. Event Flow
    2. Event Handlers
    3. The Event Object
    4. Event Types
    5. Memory and Performance
    6. Simulating Events
    7. Summary
  17. Chapter 14: Scripting Forms
    1. Form Basics
    2. Scripting Text Boxes
    3. Scripting Select Boxes
    4. Form Serialization
    5. Rich Text Editing
    6. Summary
  18. Chapter 15: Graphics With Canvas
    1. Basic Usage
    2. The 2D Context
    3. WebGL
    4. Summary
  19. Chapter 16: Html5 Scripting
    1. Cross-Document Messaging
    2. Native Drag and Drop
    3. Media Elements
    4. History State Management
    5. Summary
  20. Chapter 17: Error Handling and Debugging
    1. Browser Error Reporting
    2. Error Handling
    3. Debugging Techniques
    4. Common Internet Explorer Errors
    5. Summary
  21. Chapter 18: Xml in Javascript
    1. XML DOM Support in Browsers
    2. XPath Support in Browsers
    3. XSLT Support in Browsers
    4. Summary
  22. Chapter 19: Ecmascript For Xml
    1. E4X Types
    2. General Usage
    3. Other Changes
    4. Enabling Full E4X
    5. Summary
  23. Chapter 20: JSON
    1. Syntax
    2. Parsing and Serialization
    3. Summary
  24. Chapter 21: Ajax and Comet
    1. The XMLHttpRequest Object
    2. XMLHttpRequest Level 2
    3. Progress Events
    4. Cross-Origin Resource Sharing
    5. Alternate Cross-Domain Techniques
    6. Security
    7. Summary
  25. Chapter 22: Advanced Techniques
    1. Advanced Functions
    2. Tamper-Proof Objects
    3. Advanced Timers
    4. Custom Events
    5. Drag and Drop
    6. Summary
  26. Chapter 23: Offline Applications and Client-Side Storage
    1. Offline Detection
    2. Application Cache
    3. Data Storage
    4. Summary
  27. Chapter 24: Best Practices
    1. Maintainability
    2. Performance
    3. Deployment
    4. Summary
  28. Chapter 25: Emerging APIS
    1. RequestAnimationFrame()
    2. Page Visibility API
    3. Geolocation API
    4. File API
    5. Web Timing
    6. Web Workers
    7. Summary
  29. Appendix A: Ecmascript Harmony
  30. Appendix B: Strict Mode
  31. Appendix C: Javascript Libraries
  32. Appendix D: Javascript TOOLS
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Chapter 1

What Is JavaScript?

WHAT’S IN THIS CHAPTER?

  • Review of JavaScript history
  • What JavaScript is
  • How JavaScript and ECMAScript are related
  • The different versions of JavaScript

When JavaScript first appeared in 1995, its main purpose was to handle some of the input validation that had previously been left to server-side languages such as Perl. Prior to that time, a round-trip to the server was needed to determine if a required field had been left blank or an entered value was invalid. Netscape Navigator sought to change that with the introduction of JavaScript. The capability to handle some basic validation on the client was an exciting new feature at a time when use of telephone modems was widespread. The associated slow speeds turned every trip to the server into an exercise in patience.

Since that time, JavaScript has grown into an important feature of every major web browser on the market. No longer bound to simple data validation, JavaScript now interacts with nearly all aspects of the browser window and its contents. JavaScript is recognized as a full programming language, capable of complex calculations and interactions, including closures, anonymous (lambda) functions, and even metaprogramming. JavaScript has become such an important part of the Web that even alternative browsers, including those on mobile phones and those designed for users with disabilities, support it. Even Microsoft, with its own client-side scripting language called VBScript, ended up including ...

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