Tuesday PHP
28/12/2010
Intro to php
Php is a server side scripting language most of the websites nowadays developing using php because it is free and open source it is major tough competition to asp.net and java it has lot of inbuilt features for creating dynamic web applications it will be very helpful now maximum share of the websites in the world using php scripting and apache webserver because of its simplicity of code and extraordinary features of having it .acronym for php is “hypertext-preprocessor”
It is compatibility with all database servers mysql,sqlite,postgresql ,oracle and more
Syntax of php
There are 4 ways of syntax declaring php are
<?php ?>
<% %>
<script language=”php”>
<? ?>
Installation of php on windows
For developing web applications we need one server side scripting language and one database server and the operating system whatever it may be and the webserver is apache or IIS whatever it may be
If you go through the xampp pack we get a bundled pack of compenents:
Apache+Mysql+PHP
So the developers need not worry about the installation of xampp pack in windows
Just download the xampp pack in apachefriends.org and select for windows and just save it in which drive you want
C:/ and then change directory to xampp
After installing the xampp stack in windows u get a control panel of xampp stack just open and click the mysql and apache u enable and click start button to enable mysql and apache server
And then later
Open the firefox type this http://localhost
You get the xampp stack web appearance in your firefox desktop
Open the notepad and type the small snippet of code save it your own filename and .php with extension
<?php
Phpinfo();
?>
Save the php files in C:/xampp/htdocs/(“filename.php”)
And later check in the firefox of output of our programme just type the url location http://localhost/(“yourfilename.php”)
Above programme shows the output of php version and php information in the server
Php in Ubuntu
Download the lamp stack from apachefriends.org and extract the tar file in
tar –xvzf (latest version of lamp stack.gz file) –C /opt
u get a folder called lampp and as usual normal u go and type the code in normal note pad and save it in filesystem/var/www with .php extension
if u not have permission to write any files to that folder
sudo chmod 777 –R /var/www
it will give write permission to that particular folder in /var file system
run the code in browser http://localhost/(filename.php)
Getting started with php
php has 4 data types of variables they are
1) scalar
2) compound type
3)special data type
Scalar data types are
Integer,float,string,double
Compound date types
Array,Object
Special data types
Resource,Null
First exercise in php
<?php
echo $_SERVER[‘HTTP_USER_AGENT’];
?>
Normally php variables started with $symbol the above code output wil displays the browser information of which browser we using currently
Arrays in php
Php have 3 types of arrays they are
1)Numeric array
2)Associative array
3)Multidimensional array
1)Numeric array
1)Numeric array
It is ordinary array just we declaring the array values as usual in other languages example
<?php
$myarr = array(‘chennai’,’mumbai’,’calcutta’,’delhi’);
echo $myarr[0]
echo $myarr[1];
echo $myarr[2];
?>
The above code represents we declaring the variable $myarr and assigning the values of city names chennai,mumbai,calcutta and delhi
And printing the values of the variable $myarr[] and the position of the array
The output for the above programe is Chennai,Mumbai,calcutta
2)Associative array
In this array we assign the key values to them
Example
<?php
$myarr=array(‘sachin’=>45,’sehwag’=>75,’talent’=>’ap’);
echo $myarr[‘sachin’] ;
echo $myarr[‘sehwag’];
echo $myarr[‘talent’];
?>
We assign the key values to the above variable in $myarr we will get the output 45,75 and ap
3)Multidimensional Array
We declare array within array is called multidimensional array php has nice feature of this
Example
<?php
$myarr=array(“john”=>array(‘family’=>’chennai’,’age’=>32,’code’=>45),
‘smith’=>array(‘name’=>’school’,’age’=>42,’code’=>23));
echo $myarr[‘john’][‘family’];
echo $myarr[‘john’][‘age’];
echo $myarr[‘john’][‘code’];
echo $myarr[‘smith’][‘code’];
echo $myarr[‘smith’][‘name’];
?>
The above programme output is Chennai,32 ,45,23,school
