PHP OVERVIEW

CONTENT

Introduction of PHP

History and development

Basics of PHP programming

WHAT IS PHP ?PHP = Hypertext preprocessor

Server side scripting language

Used for development of dynamical webpagesPart of typical LAMP combination Linux, Apache, MySQL and PHP

Includes a command line scripting possibilityCan be used in graphical applications

HOW IT WORKSPHP code is usually embedded into HTML

Processing the code :The HTML code stands as it is

The PHP scripts are executed to create final HTML code

Both parts are combined and back

Resulting HTML is interpreted by a browser

ADVANTAGES OF PHP

Freely available The PHP group provides complete source code free of chargeSimilar syntax to C, PearlWorks with many operating systemsCan be deployed on many web serversInteracts with lots of databasesIt is supported by many providers of webhosting

HISTORY INITIAL DEVELOPMENTOriginally created by Rasmus LerdorfPHP originally stood for Personal Home PageReplaces small set of Pearl scriptsUsed as a tool for observing traffic on webpage

PHP 2 (PHP/FI)First publicly released version (on June 8, 1995)Combination of Lerdorfs Form Interpreter and original binary from PHP Was able to communicate with databasesEnabled the building of dynamical web applicationincluded Perl-like variables, form handling, and the ability to be embedded HTML

HISTORY RELEASED VERSIONSPHP 3The scripting core was rewritten by Zeev Suraski and Andi GutmansThe name was changed to Hypertext preprocessorIt is able to work with MS Windows and Macintosh

PHP4Added Zend engineIntroduced 'superglobals' ($_GET)

None of these versions is under development now

CURRENT VERSION - PHP 5

The most recent extension (the 5.2.6) was published on May 1, 2008Uses enhanced Zend II engine

It includes :support for object-oriented programming, the PHP Data Objects extension (simplifies accessing databases)numerous performance enhancements

WEBSITES USING PHP

More than 20 million Internet domains are hosted on servers with PHP installed

Significant examlesUser-facing portion of Facebook Wikipedia (MediaWiki) Yahoo! MyYearbook

WHAT DO YOU NEED TO WORK WITH PHP?

If your server supports PHP You dont need anythingJust create some .php files in your web directory

If your server does not support PHP, you must install PHP. Download PHPDownload database (MySQL)Download server (Apache)

BASICS OF SYNTAXScripting block starts with

Each code line in PHP must end with a (;)

Comments// ,# comment/* comment */Writing of the plain textEcho textprint text

VARIABLES IN PHPEach variable starts with $ symbol

Variable name can contain only a-Z,0-9,_

It does not need to be declared before its setting.

VARIABLE TYPES

NumericalInteger positive as well as negative, including 0Float real numbers, 14 digits accuracy

Logical Boolean - True x False, not case sensitive

Alphabetical String set of characters

WORKING WITH VARIABLESSettype($var, integer)allows you to set variable according to your wishGettype() write the type of variable

(.) Connects 2 variables of string typestrlen() finds the length of a string

PHP OPERATORSUses standard mathematical operators +,-,/,* Special symbol ++ (--) for increase (decrease) by 1

Comparison operators >,=Special cases == is equal!= is different

Assignment operators x+=y x=x+y

LOGICAL OPERATORS

&& = and|| = orAt least one of condition is fulfilled! = notxorExactly one statement is evaluated as true

CONDITIONAL STATEMENTSIf/ else After each statement stands (;) If more than one command should be executed, use curly braces { }

Switch / breakUsed for choosing one possibility from multiple casesSwitch ($var ){ case : x : echo good; break;default : echo wrong input ;}

ARRAYS IN PHP

Numeric arrayEach element of array has its ID number (first 0!!)$names = array("Petr,"Joe");$names[0] = "Petr";

Associative ArraysEach element is assigned its value$ages = array("Peter"=>32, "Joe"=>34);$ages['Peter'] = "32";

MULTIDIMENSIONAL ARRAYSelement of array is also an array

$families = array ("Griffin"=>array ( "Peter", "Lois", "Megan" ), "Soltis" =>array(Johny", "Morgan" ))

PHP LOOPINGwhile loops repeat until final condition is reached$i =1;while ($i

PHP LOOPINGfor Repeats the specific part of code so many times we choose

for ($i=1; $i

HTML INSIDE PHPIf inside quotes, the Html tags are returned as a text by PHP moduleTreated as a HTML tag by

PHP FUNCTIONS

All function starts with function($parameter)Requirements for naming functions are same as these for variables The { mark opens the function code, while }mark closes itIt can have either defined or no parameter

More than 700 built-in functions available

PHP FORMS AND USER INPUTUsed to gain information from users by means of HTMLInformation is worked up by PHP

Name: Age:

THE $_GET VARIABLEUsed to collect values from a formDisplays variable names and values are in the URLhttp://www.w3schools.com/welcome.php?name=jo&age=39Can send limited amount of information (max. 100 characters)

Welcome You are years old

THE $_POST VARIABLEUsed to collect values from a formInformation from a form is invisiblehttp://www.w3schools.com/welcome.phpNo limits on the amount of information to be send

Welcome You are years old.

THANK YOU FOR YOUR ATTENTION !

SOURCEShttp://www.w3schools.com/PHP/http://en.wikipedia.org/wiki/PHPhttp://cz.php.net/http://www.linuxsoft.cz/