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8 th Semester, Batch 2009 Department Of Computer Science SSUET
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8th Semester, Batch 2009Department Of Computer Science
SSUET
Web Server Software & Programming/Scripting Language: When setting out to build a site, products
you need are as follows.Web server softwareDatabase management systemProgramming/scripting languageHardware for the web serverAn Operating system
Web Server Software & Programming/Scripting Language:Some of these are dependent on others for
example not all operating run on all hardware and not all scripting can connect to any other database. From the above products for developing any website the three main ingredients that plays major role for developing websites, and to work the websites professionally, for retrieving web pages, ensuring secure data storage are Web server soft wares , database management system, scripting language.
Web Server Software:A computer program that is responsible for
accepting HTTP requests from web clients, which are known as web browsers and serving them HTTP responses along with optional data contents, which usually are web pages such as HTML documents and linked objects (images, etc.).
Internet Information server IISApache
Database management system:A database management system should be
there at server side, which enables you to store, retrieve, search and sort the data. The database should provide access to the data; it must allow multiple user access concurrently and only authorized person access.
Sql ServerMy SqlOracle
Programming/Scripting Language:Programming languages are used to design
your web pages. The choice of programming depend on that it should have easy connectivity with the database, it should be platform independent
ASP.NetPHPJava server pagesPerl
What is PHP?PHP is a server side scripting language
designed for developing websites. Within an HTML page you can embed PHP code which is executed each time the page is visited. Your page is interpreted at web server and generates HTML code, which your browser can understand.
What is MySQL?MySql is a fast, robust database management
system, which enables you for the data accessing according to request. Mysql control accessing of the data to ensure that multiple user can work with it concurrently, so that the accessing to the data can be possible through world wide.
Some of PHP’s Strength:PHP also offers features like other programming
language like high performance, integration to many different databases, built in libraries, strong object oriented support, but the main features which can meet the requirement that make the PHP best choice are:
CostPortabilityOpen source
Some of PHP’s Strength:Cost:PHP is free. You can download the latest version at any time for no
cost. Portability:PHP can work on Cross platform. You can write your PHP code
on multiple platforms. It will work on UNIX, Linux, Solaris or any other version of Microsoft Windows, due to this nature it offers;
LAMPP(Linux Apache MySQL PHP)WAMPP(Windows Apache MySQL PHP)
Open Source:You have access to PHP source code it does not demand for any
license. Unlike closed source product you are free to make any change to the code
Basic PHP Syntax:A PHP scripting block always starts with <?
php and ends with ?>. 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.
Basic PHP Syntax:Example:<html><body> <?phpecho "Hello World";?> </body></html>
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
Comments in PHP:In PHP, we use // to make a single-line comment
or /* and */ to make a large comment block.Example:<html><body><?php// This is a comment/* This is a comment block */ ?></body></html>
Variables in PHP:The correct way of setting a variable in PHP:Example1:$var_name = value; Example2:<?php$txt = "Hello World!";$number = 16;?>
PHP is a Loosely Typed Language:In PHP a variable does not need to be
declared before being set. In the example above, you see that you do not have to tell PHP which data type the variable is. PHP automatically converts the variable to the correct data type, depending on how they are set. In a strongly typed programming language, you have to declare (define) the type and name of the variable before using it. In PHP the variable is declared automatically when you use it.
Strings in PHPExample<?php$txt="Hello World";echo $txt;?>
The Concatenation Operator:There is only one string operator in PHP. The
concatenation operator (.) is used to put two string values together. To concatenate two variables together, use the dot (.) operator.
Example:<?php$txt1="Hello World";$txt2="1234";echo $txt1 . " " . $txt2;?>
The Concatenation Operator:Output of the code above is:Hello World 1234
Using the strlen() function:The strlen () function is used to find the
length of a string.Example:<?phpecho strlen("Hello world!");?> The output of the code above will be:12
Using the strpos() functionThe strpos() function is used to search for a
string or character within a string. If a match is found in the string, this function will return the position of the first match. If no match is found, it will return FALSE.
Example:<?phpecho strpos("Hello world!","world");?>
Using the strpos() functionThe Output of the above code is. 6As you see the position of the string "world"
in our string is position 6. The reason that it is 6, and not 7, is that the first position in the string is 0, and not 1.
Conditional Statementsif...else statement - use this statement if
you want to execute a set of code when a condition is true and another if the condition is not true
elseif statement - is used with the if...else statement to execute a set of code if one of several condition are true
The If...Else StatementIf you want to execute some code if a
condition is true and another code if a condition is false, use the if.... else statement.
Syntax:if (condition) code to be executed if
condition is true;else code to be executed if condition is false;
The If...Else StatementExample:<html><body><? php$d=date("D");if ($d=="Fri") echo "Have a nice weekend!"; else echo "Have a nice day!"; ?></body></html>
The ElseIf StatementIf you want to execute some code if one of
several conditions are true use the elseif statement Syntax:
if (condition) code to be executed if condition is true;
elseif (condition) code to be executed if condition is true;
else code to be executed if condition is false;
The ElseIf Statement Example: The following example will output "Have a nice weekend!" if the current
day is Friday, and "Have a nice Sunday!" if the current day is Sunday. Otherwise it will output "Have a nice day!".
<html> <body> <?php $d=date("D"); if ($d=="Fri") echo "Have a nice weekend!"; elseif ($d=="Sun") echo "Have a nice Sunday!"; else echo "Have a nice day!"; ?> </body> </html>
The PHP Switch StatementUse the switch statement to select one of many blocks
of code to be executed.Syntaxswitch (n)
{case label1: code to be executed if n=label1; break;case label2: code to be executed if n=label2; break;default: code to be executed if n is different from both label1 and label2;}
The PHP Switch Statement Example <html>
<body>
<?phpswitch ($x){case 1: echo "Number 1"; break;case 2: echo "Number 2"; break;case 3: echo "Number 3"; break;default: echo "No number between 1 and 3";}?>
</body></html>
