JavaScript: Visual QuickStart Guide, Eighth Edition

7. Forms and Regular Expressions

In This Chapter

Validating an Email Address with Regular Expressions 173

Validating a File Name 178

Extracting Strings 180

Formatting Strings 183

Formatting and Sorting Strings 187

Formatting and Validating Strings 189

Replacing Elements using Regular Expressions 192

Regular expressions are an amazingly powerful way to validate and format text strings. Using regular expressions, you can write a line or two of JavaScript code that can accomplish tasks that otherwise would have taken several dozen lines.

A regular expression (often abbreviated as RegExp or called by its synonym grep) is a pattern, written using special symbols, which describes one or more text strings. You use regular expressions to match patterns ...