What is PHP?
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Transcript What is PHP?
What is PHP?
PHP (recursive acronym for "PHP: Hypertext
Preprocessor") is a widely-used Open Source generalpurpose scripting language that is especially suited for Web
development and can be embedded into HTML.
What can PHP do?
Server-side Scripting:
This is the most traditional and main target field for PHP. You need three
things to make this work:
1. The PHP parser (CGI or server module)
2. A web browser
3. A webserver with a connected PHP installation.
All these can run on your home machine if you are just experimenting
with PHP programming.
What can PHP do?
Command Line Scripting:
You can make a PHP script to run it without any server or browser. You
only need the PHP parser to use it this way. This type of usage is ideal
for scripts regularly executed using cron (on *nix or Linux) or Task
Scheduler (on Windows). These scripts can also be used for simple text
processing tasks.
What can PHP do?
Desktop Applications:
Writing desktop applications. PHP is probably not the very best
language to create a desktop application with a graphical user interface,
but if you know PHP very well, and would like to use some advanced
PHP features in your client-side applications you can also use PHPGTK to write such programs. You also have the ability to write crossplatform applications this way.
Database Strength:
Adabas D
dBase
Empress
FilePro (read-only)
Hyperwave
IBM DB2
Informix
InterBase
PostgreSQL
FrontBase
mSQL
SQLite
Solid
Direct MS-SQL
MySQL
ODBC
Sybase
Velocis
Unix dbm
Oracle (OCI7 and OCI8)
Ingres
Ovrimos
Ubiquitous Setups:
- Most commonly used with Apache Web Server as module
- Most commonly used with MySQL Database Server
- Most commonly used on the Linux platform
Additional Common Setups:
- Growing number of installations on Windows machines
- Local development setups are popular
19/562,759 Domains, 1,305,799 IP Addresses
Simple Web Page Example:
helloworld.php
<html>
<head>
<title>Example</title>
</head>
<body>
<?php
echo ‘Hello, world!’;
?>
</body>
</html>
The Guts
Variables:
- variables are given a value at declaration but not a type
$foo = 0;
- always preceded by the dollar sign: $
- vars can be converted to common specific types
(int, variant, etc.)
- typical scope rules apply, but global command may be used
for public or global variables
The Guts
Functions:
- typically declared in “global” files that are included by all your other
website pages -> keep them in one place
- optionally with arguments and can return values
<?php
function fooFunction($arg1, $arg2 = '')
{
if (condition)
{
statement;
}
return $val;
}
?>
The Guts
Classes:
- more forgiving than in C++, VB, C# or similar approaches
- excellent way to encapsulate and control code
<?php
class clsFoo
{
var $my_color = ‘green’;
function clsFoo ($arg1)
{
$this->my_color = $arg1;
}
}
?>
Where to Start?
- www.php.net
- www.phpmyadmin.net (best free MySQL management tool)
- www.mysql.org (.com)
- www.apache.org (version 1.3.x recommended for a local install)
- www.jtlnet.com (cheap php/mysql hosting – tons out there)
- www.phpbuilder.com (coding resource)
- www.zend.com (Zend Studio 5.x – Visual Studio-type IDE)