Defining Regular Expressions
Using Regular Expressions in PHP Scripts
Parsing is the act of breaking a whole into components, usually a sentence into words. PHP must parse the code you write as a first step in turning a script into an HTML document. There will come a time when you are faced with extracting or verifying data collected in a string. This could be as simple as a tab-delimited list. It could be as complicated as the string a browser uses to identify itself to a Web server. You may choose to tokenize the string, breaking it into pieces. Or you may choose to apply a regular expression. This chapter examines PHP's functions for parsing and string ...