John Paul Mueller - Java eLearning Kit For Dummies

Java eLearning Kit For Dummies

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Copyright 2014 by John Wiley & Sons, Inc., Hoboken, New Jersey

Published by John Wiley & Sons, Inc., Hoboken, New Jersey

Published simultaneously in Canada

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Library of Congress Control Number:

ISBN 978-1-118-09878-3 (pbk); ISBN 978-1-118-22370-3 (ebk); 978-1-118-23706-9 (ebk);
ISBN 978-1-118-26201-6 (ebk)

Manufactured in the United States of America

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Chapter 1

• Javas increasing popularity makes it the most common language used to develop cross-platform applications.
• Developers rely on the fact that Java is a standards-based language.
• Each platform that Java supports has its own version of the Java Software Development Kit (SDK) and Java Runtime Engine (JRE), yet uses precisely the same language.
• All Java applications share common components.
• Java applications rely on a special application called a compiler to change Java source code that the developer understands to an executable form that the JRE understands.
• Use comments to make it easier to remember what tasks your application performs.
• Java applications rely on the Java Application Programming Interface (API) to perform many tasks.
• Develop a better understanding of Java by viewing the help files.

1. What are the advantages of using a language that works across multiple platforms?

   Cross-platform compatibility is a major advantage of using Java, as described on page

2. Where can I obtain a copy of the Java SDK?

   You can find the installation and configuration instructions for the Java SDK starting on page

3. Do I absolutely have to use an Integrated Development Environment (IDE)?

   Java makes it quite easy to use a simple text editor to create programs, but youll do much better if you rely on an IDE as described on page

4. What are the main parts of a Java application?

   You can find a description of the major parts on page

5. What purpose does the.classfile serve?

   A .class file contains the byte code executed by the JRE as described on page

6. Why is the JavaW command important?

   Discover the JavaW difference on page

7. When should I comment my code?

   There are distinct times when you should consider commenting your code, as explained on page

8. Where do I find an explanation of the Java API content?

   The Java API contains all the standard classes used to create applications, and you can find out about it on page

9. Must I go online to get help?

   Java provides both local and online help, as described on page

Java is an amazing language. Most programming languages are designed around a single operating system or environment. For example, when you work with the Microsoft .NET Framework languages, such as C# or Visual Basic, youre working with Windows unless you get a special third-party product to make these languages work elsewhere. Likewise, Macintosh developers commonly use Objective C to create their applications. Using PHP means that youre creating applications that appear in a browser, rather than applications that run within the host operating system. Java crosses all these boundaries. You can find Java running on just about every operating system, and Java applications can run both within the operating system environment and as part of a browser presentation.