Introduction to PHP

What is PHP?

• PHP stands for PHP: Hypertext Preprocessor
• PHP is a server-side scripting language, like ASP, Coldfusion, Perl
• PHP is a programming language was designed for creating dynamic websites
• PHP supports many databases like MySQL, Informix, Oracle, Sybase, Solid, PostgreSQL, Generic ODBC, etc.
• PHP is an open source software and you can download free from www.php.net.

Why PHP?

• PHP is easy to learn and runs efficiently on the server side
• PHP runs on different platforms like Windows, Linux, Unix, etc.
• PHP is compatible with almost all servers used today like Apache, IIS, etc. .

What is an PHP File?
An PHP file is a text file that contains HTML, XML Tags, Text and scripts. The scripts in PHP files are excuted on the server. The file extension of PHP file is ".php".

PHP Requirements

• Install Apache Web Server on Windows, unix or linux operatings system you can download Apache web server from http://httpd.apache.org/download.cgi
• Then insall PHP on Windows, unix or linux operatings system you can download PHP software from http://www.php.net/downloads.php
• Install MySQL on Windows, unix or linux operatings system you can download PHP software from http://www.mysql.com/downloads/index.html

PHP Tags

PHP has following tags:

First PHP Script 

For write first script of PHP, Open notepad. Type the below example and save the file at C:\apache\htdocs\filename.php,

In this script <?php is used for start PHP tag.

print is used to print any statement on page. Another function echo is also to print any statement on page.

semicolon (;) is used for end any statement .

?> is used for end php script

Comments in PHP

Comments are used for ignore any statements.There are two comment tags used in PHP.

// (Single Line Comments ) will comment out a single line of coding.

/* */ (Multiple Line Comments ) will comment out a block of code.