文档介绍：PHP Language Basics
Active Server Pages (PHP) is a proven, well-established technology for building dynamic Web applications, which provides the power and flexibility you need to create anything from a personal, Web based photo gallery to plete catalogue and shopping cart system for your next eCommerce project。 One unique feature of PHP is that it lets you choose your favourite scripting language, be it JavaScript or PHP ; however, PHP is by far the most popular choice. In this article, I'll bring you up to speed on the basic syntax of the PHP language, including variables, operators, and control structures.
This article is the second in a series teaching PHP. Specifically, the goal of this series is to teach you all you need to know to create dynamic Web sites using PHP. This article picks up right where the previous article in the series, Getting Started with PHP, left off.
Variables
Here is the listing for the first PHP script I helped you create in the previous article:
1 <html>
2 <head>
3 <title> My First PHP Page </title>
4 </head>
5 <body>
6 <?php
7 ' Write out a simple HTML paragraph
8 Echo "<p>This is a test of PHP.</p>"
9 ?>
10 </body>
11 </html>
As I admitted in that article, this is a pretty uninteresting example of an PHP script. When es right down to it, this script doesn't do anything a plain, old HTML page couldn't do. Oh sure, I gave a slightly more interesting example that displayed the current server time, but to be really useful a script needs to perform some form of calculation, or manipulate dynamic information to present it in some interesting way.
The language used for writing most PHP programs, and which I'll be using throughout this series, is called PHP . Like most programming languages, PHP lets you store data in variables. A variable may be thought of simply as a named location in memory where data may be stored. PHP is what is known as a loosely typed language, which means that a particular variable may store