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Maged Bouchahma University of Nizwa
Introduction to PHP Maged Bouchahma University of Nizwa B. Maged
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Introduction to PHP PHP Hypertext Preprocessor. Other Names : Personal Home Page, Professional Home Page Is a server side scripting language. Capable of generating the HTML pages HTML generates the web page with the static text and images. However the need evolved for dynamic web based application, mostly involving database usage. B. Maged
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WEB SERVER Gets Page Server response CLIENT Hello <HTML>
HTTP Request (url) <HTML> <?php PHP code ?> </HTML> Gets Page <HTML> <B>Hello</B> </HTML> Interprets the PHP code CLIENT Server response Browser creates the web page Hello B. Maged
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Why PHP? ..there are no. of server side scripting available like ASP, SSJS, JSP….. PHP involves simplicity in scripting (..generally using the database) platform independence. PHP is primarily designed for web applications well optimized for the response times needed for web applications Is an open source. B. Maged
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PHP Language features PHP language features such as control structures, operators, variable types, function declaration, class/object declaration are almost similar to any compiled or interpreted language such as C or C++. B. Maged
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PHP Data Type Three basic data types More data types
Integer Double String More data types Array Object PHP is an untyped language variables type can change on the fly. B. Maged
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PHP Block PHP code block is embedded within the <?php and ?> tags. When the server encounters the PHP tags it switches from the HTML to PHP mode. There are four different ways to embed the PHP code <?php echo(“Some PHP code”); ?> <? echo(“Some PHP code”); ?> <SCRIPT Language=‘php’> echo(“Some PHP code”); </SCRIPT> <% echo(“Some PHP code”); %> B. Maged
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PHP Constants ..values that never changes
Constants are defined in PHP by using the define() function. For e.g. define(“NCST”, “National Centre for Software Technology”) defined() function says whether the constant exists or not. B. Maged
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PHP Variables The variables in PHP are declared by appending the $ sign to the variable name. For e.g $company = “NCST”; $sum = 10.0; variable’s data type is changed by the value that is assigned to the variable. Type casting allows to change the data type explicitly. B. Maged
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PHP Variables (cont.) Rich set of functions for working with variable.
For e.g gettype, settype, isset, unset, is_int, intval etc etc B. Maged
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PHP Operators All the operators such as arithmetic, assignment, Comparison, and logical operators are similar to the operators in C and C++. In PHP the string concatenation operator is denoted by ‘.’. For e.g. $name = “My name is”.$myname; B. Maged
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PHP Statements IF statement Alternative Syntax if(<condition>) :
//php code goes here } else { Alternative Syntax if(<condition>) : //html code goes here else : endif; B. Maged
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PHP Statements (cont.) For loop While loop Do-While loop
for($i=0;$i < 10;$++i) { echo(“the value is :”. $i); } Alternative Syntax for($i=0;$i < 10;$++i) : // html code goes here endfor; While loop Do-While loop B. Maged
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Functions Function declaration in PHP
function my_func(<parameters>) { //do something in the function } for e.g. function sayHello() { echo(“<B>hello amrish<B><BR>”); B. Maged
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Functions (cont.) Assigning functions to the variables
for e.g $hello = “my_func”; to invoke the function my_func() through the variable $hello( ); When an argument is to be passed by reference, an ampersand (&) is placed before the parameter name for e.g. my_func(&$my_refvar); B. Maged
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Arrays ..contains value set
each element has a value, data stored in the element. And has a key by which the element can be referred to. B. Maged
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Initializing Arrays No of ways to initialize the array. For e.g.
$ncststaff[] = “amrish”; $ncststaff[] = “murali”; $ncststaff[] = “narayan”; $ncststaff[123] = “amrish”; $ncststaff[122] = “murali”; $ncststaff[121] = “narayan”; $ncststaff = array (“amrish”, “murali”, “narayan”); to change the indices of the array use => operator. B. Maged
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Accessing the Array Elements
The elements in the array can be accessed by using the list and each constructs for e.g while(list($key,$value) = each(countries)) echo(“$value<BR>\n”); current(<arrayname>) gives the current value being accessed. key(<arrayname>) gives the index of the current element that is being accessed. prev(<arrayname>) gives the previous element. next(<arrayname>) gives the next element. B. Maged
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Accessing the Array Elements (cont.)
Array_walk(<arrayname>,<function_name>) function_name is the function that is written for every member of an array. For e.g $ncststaff = array (“amrish”, “murali”, “narayan”); array_walk ($ncststaff, printstaff); // function to print each element of the array function printstaff($names) { echo “<B>$names</B><BR>\n”; } B. Maged
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Arrays (cont.) Sorting Functions creates a two dimensional array.
$ncststaff = array (“dake” => array(“amrish”, “lakshana”, “venkat”), “spc” => array(“narayan”, “murali”,“prasad”)); creates a two dimensional array. Sorting Functions sort() : sorts the elements in the numeric and alphabetical order. rsort() : sorts the elements in the reverse order. asort() : sorts the elements in the array without changing the indices. ksort() : sorts the arrays by key. B. Maged
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Classes Class is a template of an object and includes the properties and methods that describe an object and behavior. Class in PHP is defined using class statement. B. Maged
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Classes (cont.) For e.g // define the properties var $companyname;
<? class company { // define the properties var $companyname; // define the methods function company($cname) { $this->companyname = $cname; } function getnames($idcode) { //return the name of the employee for the required idcode ?> B. Maged
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PHP Richness PHP comes with myriad of options i.e. supports several APIs and interfaces to other programming tools such as Database connectivity. LDAP XML Mail protocols such as IMAP, SMTP Image functions etc…. B. Maged
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Support for Regular Expressions
Not pretty things to look at and work with. E.g. PHP takes over the headache from the programmers for explicitly coding for pattern matching. Functions: ereg() and eregi() ereg_replace() & eregi_replace() split() B. Maged
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Image Generation & Manipulation
PHP offers powerful set of functions for generating and manipulating the images. Rendering regular geometric figures, modifying images manipulate text, font and color and even the pixels in the image. ….creating the images on the fly. B. Maged
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Image Generation & Manipulation (cont.)
PHP uses the GD library for the most of the image functionality that it offers. GD library is used for generating the two-dimensional graphics. PHP API’s provides us with functions to: Create, delete, resize and modify images. Draw basic geometric figures Manipulate text and fonts Manipulate colors Interlace and manipulate pixels Handle PostScript files B. Maged
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Mailing functions Sending E-Mails Receiving E-Mails Mail()
Used to send simple text messages. Depends on the local mail delivery system. Using SMTP Accepts the for every recipient and goes through trouble of delivering the s. Receiving s PHP works out well with the IMAP protocol. Rich set of support functions Imap_open, impa_delete, imap_close, imap_mail_copy, imap_mail_move etc. B. Maged
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PHP-Database Connectivity
Supports APIs for accessing large number of databases. ODBC is a standard API for accessing a database that has PHP support. B. Maged
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PHP-Database Connectivity
Some of Oracle 8.x functions. OCILogon OCILogoff OCIParse OCIFetch; OCIFetchInto; OCIFetchStatement OCIExecute OCIFreeStatement B. Maged
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LDAP Support in PHP PHP provides LDAP API’s that allows the programmers to create LDAP clients; by providing transparent access to backend LDAP directory servers. For e.g. Web based client. Telephone Directory. B. Maged
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XML Support in PHP PHP supports a set of functions that can be used for writing PHP-based XML applications. These functions are used for parsing well formed XML document. B. Maged
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References Professional PHP programming www.phpbuilder.com www.php.net
By Jesus Castagnetto, Chris Schollo et al B. Maged
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THANK YOU B. Maged
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