Book Image

Object-Oriented JavaScript - Second Edition

Book Image

Object-Oriented JavaScript - Second Edition

Overview of this book

JavaScript is the behavior, the third pillar in today's paradigm that looks at web pages as something that consists of clearly distinguishable parts: content (HTML), presentation (CSS) and behavior (JavaScript). Using JavaScript, you can create not only web pages but also desktop widgets, browser and application extensions, and other pieces of software. It's a pretty good deal: you learn one language and then code all kinds of different applications. While there's one chapter specifically dedicated to the web browser environment including DOM, Events and AJAX tutorials, the rest is applicable to the other environments Many web developers have tried coding or adopting some bits of JavaScript, but it is time to "man up" and learn the language properly because it is the language of the browser and is, virtually, everywhere. This book starts from zero, not assuming any prior JavaScript programming knowledge and takes you through all the in-depth and exciting futures hidden behind the facade. Once listed in the "nice to have" sections of job postings, these days the knowledge of JavaScript is a deciding factor when it comes to hiring web developers. After reading this book you'll be prepared to ace your JavaScript job interview and even impress with some bits that the interviewer maybe didn't know. You should read this book if you want to be able to take your JavaScript skills to a new level of sophistication.
Table of Contents (19 chapters)
Object-Oriented JavaScript Second Edition
Credits
About the Authors
About the Reviewer
www.PacktPub.com
Preface
Built-in Functions
Regular Expressions
Index

Switch


If you find yourself using an if condition and having too many else if parts, you could consider changing the if to a switch:

var a = '1',
    result = '';
switch (a) {
case 1:
  result = 'Number 1';
  break;
case '1':
  result = 'String 1';
  break;
default:
  result = 'I don\'t know';
  break;
}

The result after executing this is "String 1". Let's see what the parts of a switch are:

  • The switch statement.

  • An expression in parentheses. The expression most often contains a variable, but can be anything that returns a value.

  • A number of case blocks enclosed in curly brackets.

  • Each case statement is followed by an expression. The result of the expression is compared to the expression found after the switch statement. If the result of the comparison is true, the code that follows the colon after the case is executed.

  • There is an optional break statement to signal the end of the case block. If this break statement is reached, the switch is all done. Otherwise, if the break is missing, the program...