Web Coding & Development All-in-One For Dummies, 2nd Edition

Chapter 9

Manipulating Strings, Dates, and Numbers

IN THIS CHAPTER

Manipulating strings

Working with dates and times

Performing math calculations

First learn computer science and all the theory. Next develop a programming style. Then forget all that and just hack.

— GEORGE CARRETTE

Although your JavaScript code will spend much of its time dealing with web page knickknacks such as HTML tags and CSS properties, it will also perform lots of behind-the-scenes chores that require manipulating strings, dealing with dates and times, and performing mathematical calculations. To help you through these tasks, in this chapter you explore three of JavaScript’s built-in objects: the String object, the Date object, and the Math object. You investigate the most important properties of each object, master the most used methods, and encounter lots of useful examples along the way.

Manipulating Text with the String Object

I've used dozens of examples of strings so far in this book. These include not only string literals (such as "Web Coding and Development For Dummies") but also methods that return strings (such as the prompt() method). So it should be clear by now that strings play a major role ...