Beginning JavaScript, 5th Edition

2Data Types and Variables

WHAT YOU WILL LEARN IN THIS CHAPTER:                

• Representing data in code
• Storing data in memory
• Making calculations
• Converting data

WROX.COM CODE DOWNLOADS FOR THIS CHAPTER

You can find the wrox.com code downloads for this chapter at http://www.wiley.com/go/BeginningJavaScript5E on the Download Code tab. You can also view all of the examples and related files at http://beginningjs.com.

One of the main uses of computers is to process and display information. By processing, we mean the information is modified, interpreted, or filtered in some way by the computer. For example, on an online banking website, a customer may request details of all money paid out from his account in the past month. Here the computer would retrieve the information, filter out any information not related to payments made in the past month, and then display what’s left in a web page. In some situations, information is processed without being displayed, and at other times, information is obtained directly without being processed. For example, in a banking environment, regular payments may be processed and transferred electronically without any human interaction or display.

In computing, information is referred to as data. Data comes in all sorts of forms, such as numbers, text, dates, and times, to mention just a few. In this chapter, you look specifically at how JavaScript handles data such as numbers and text. An understanding of how data is handled is fundamental to ...