What You Should Already Know
Before you continue you should have a basic understanding of the following:
- HTML / XHTML
- Some scripting knowledge
If you want to study these subjects first, find the tutorials on our Home page.
What is PHP?
- PHP stands for PHP: Hypertext Preprocessor
- PHP is a server-side scripting language, like ASP
- PHP scripts are executed on the server
- PHP supports many databases (MySQL, Informix, Oracle, Sybase, Solid, PostgreSQL, Generic ODBC, etc.)
- PHP is an open source software (OSS)
- PHP is free to download and use
What is a PHP File?
- PHP files may contain text, HTML tags and scripts
- PHP files are returned to the browser as plain HTML
- PHP files have a file extension of “.php”, “.php3”, or “.phtml”
What is MySQL?
- MySQL is a database server
- MySQL is ideal for both small and large applications
- MySQL supports standard SQL
- MySQL compiles on a number of platforms
- MySQL is free to download and use
PHP + MySQL
- PHP combined with MySQL are cross-platform (means that you can develop in Windows and serve on a Unix platform)
- PHP runs on different platforms (Windows, Linux, Unix, etc.)
- PHP is compatible with almost all servers used today (Apache, IIS, etc.)
- PHP is FREE to download from the official PHP resource: www.php.net
- PHP is easy to learn and runs efficiently on the server side
Where to Start?
- Install an Apache server on a Windows or Linux machine
- Install PHP on a Windows or Linux machine
- Install MySQL on a Windows or Linux machine
What do You Need?
This tutorial will not explain how to install PHP, MySQL, or Apache Server.
If your server supports PHP – you don’t need to do anything! You do not need to compile anything or install any extra tools – just create some .php files in your web directory – and the server will parse them for you. Most web hosts offer PHP support.
However, if your server does not support PHP, you must install PHP. Below is a link to a good tutorial from PHP.net on how to install PHP5:
Download PHP for free here: http://www.php.net/downloads.php
Download MySQL Database
Download MySQL for free here: http://www.mysql.com/downloads/index.html
Download Apache Server
Download Apache for free here: http://httpd.apache.org/download.cgi
You cannot view the PHP source code by selecting “View source” in the browser – you will only see the output from the PHP file, which is plain HTML. This is because the scripts are executed on the server before the result is sent back to the browser.
Basic PHP Syntax
A PHP scripting block always starts with <?php and ends with ?>. A PHP scripting block can be placed anywhere in the document.
On servers with shorthand support enabled you can start a scripting block with <? and end with ?>.
However, for maximum compatibility, we recommend that you use the standard form (<?php) rather than the shorthand form.
A PHP file normally contains HTML tags, just like an HTML file, and some PHP scripting code.
Below, we have an example of a simple PHP script which sends the text “Hello World” to the browser:
<?php echo "Hello World"; ?>
Each code line in PHP must end with a semicolon. The semicolon is a separator and is used to distinguish one set of instructions from another.
There are two basic statements to output text with PHP: echo and print. In the example above we have used the echo statement to output the text “Hello World”.
Comments in PHP
In PHP, we use // to make a single-line comment or /* and */ to make a large comment block.
//This is a comment
/* This is a comment block */