Sams Teach Yourself JavaScript in 24 Hours

By Michael Moncur

• Table of Contents
  • Copyright
  • About the Author
  • Acknowledgments
  • We Want to Hear from You!
  • Reader Services
  • Introduction
  • Part I: Getting Started
  • Hour 1. Understanding JavaScript
  • Hour 2. Creating a Simple Script
    • Tools for Scripting
    • What Time is It?
    • Beginning the Script
    • Adding JavaScript Statements
    • Creating Output
    • Adding the Script to a Web Page
    • Testing the Script
    • Workshop: Hiding Scripts from Older Browsers
    • Summary
    • Q&A
    • Quiz
    • Exercises
  • Hour 3. How JavaScript Programs Work
  • Part II: Learning JavaScript Basics
  • Hour 4. Using Functions and Variables
  • Hour 5. Using Strings and Arrays
  • Hour 6. Testing and Comparing Values
  • Hour 7. Repeating Yourself: Using Loops
  • Hour 8. Using Math and Date Functions
  • Part III: The Document Object Model (DOM)
  • Hour 9. Working with the Document Object Model
  • Hour 10. Responding to Events
  • Hour 11. Using Windows and Frames
  • Hour 12. Getting Data with Forms
  • Hour 13. Using Graphics and Animation
  • Part IV: Moving on to Advanced JavaScript Features
  • Hour 14. Creating Cross-Browser Scripts
  • Hour 15. Creating Custom Objects
  • Hour 16. Working with Sounds and Plug-Ins
  • Hour 17. Debugging JavaScript Applications
  • Part V: Working with Dynamic HTML (DHTML)
  • Hour 18. Working with Style Sheets
  • Hour 19. Using Dynamic HTML (DHTML)
  • Hour 20. Using Advanced DOM Features
  • Part VI: Putting It All Together
  • Hour 21. Improving a Web Page with JavaScript
  • Hour 22. Creating a JavaScript Game
  • Hour 23. Creating DHTML Applications
  • Hour 24. JavaScript Tips and Tricks
  • Part VII: Appendices
  • Appendix A. Other JavaScript Resources
  • Appendix B. Tools for JavaScript Developers
  • Appendix C. Glossary
  • Appendix D. JavaScript Quick Reference
  • Appendix E. DOM Quick Reference

Creating Output

You now have two variables—localtime and utctime—which contain the results we want from our script. Of course, these variables don't do us much good unless we can see them. JavaScript includes a number of ways to display information, and one of the simplest is the document.write statement.

The document.write statement displays a text string, a number, or anything else you throw at it. Since your JavaScript program will be used within a Web page, the output will be displayed as part of the page. To display the result, add these statements before the final </script> tag:

document.write("<b>Local time:</b> " + localtime + "<br>");
document.write("<b>UTC time:</b> " + utctime);

These statements tell the browser to add some text to the Web page containing your script. The output will include some brief strings introducing the results, and the contents of the localtime and utctime variables.

Notice the HTML tags, such as <b>, within the quotation marks—since JavaScript's output appears within a Web page, it needs to be formatted using HTML. The <br> tag in the first line ensures that the two times will be displayed on separate lines.

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