1. Server-Side Application and Data Management IT IS 3105 (Spring 2010)
Lecture 3

2. What is PHP? http://theopensourcery.com/phpover.htm
Server-side interpreter which is Open Source and free
Growing number of PHP web applications
Start at PHP Resources
Provides familiar syntax to C, Perl and Java developers
Fast connections to popular databases
Fast native connections to the Open Source MySQL database
Runs reliably on Windows, Linux and Mac servers and clients
Web pages run reliably on all the popular browsers
Associative arrays are very useful for UI and database apps
Object oriented classes are easy to understand
Links to PDF, SWF, XML, Java, etc, etc.

3. Home site: HOME Site: Stats http://www.php.net/
Usage:

4. XAMPP In my examples XAMPP has been installed in: Apache root:
c:\xampp
Apache root:
C:\xampp\htdocs
directed to the Apache root
Put web files into the Apache root

5. Testing PHP php –v XAMPP in Windows
If php is installed and configured it will return the version number
XAMPP in Windows
Sets environment
Run from “shell”

6. Testing apache/php http://localhost Create simple test webpage:
Will show XAMPP home page
Uses the “magic” of the index.php default
Create simple test webpage:
Figure 1-2 on page 7 of Spring into PHP5
Save in c:/xampp/htdocs as ajktest1.php
Default root for XAMPP Apache install
Mixture of HTML and PHP
Will display php installation information

7. Mixing HTML and PHP Can mix HTML and php code! Source: to view:
c:\xampp\htdocs\PHPBookExamples\ch01\phphtml.php
to view:

8. Some php Basics Interpreted Language
All commands must be terminated with a “;”
Contrast that to JavaScript
Weakly typed language
Data is interpreted for best type
Programmer must use care in storing and retrieving data

9. Printing ECHO... ECHO... ECHO... ECHO... ECHO...
Sends the quoted text to the stdout
echo “This is a test”;

10. Special Print Characters (escape sequences)
\n Newline
\r Carriage return
\t Tab
\\ Prints a \
\$ Prints a $
\” Prints a “
\0 to \777 Prints a character based on the octal value
\x0 to \xFF Prints a character based on the hexadecimal value

11. Quote notes Single and Double quote have similar but different uses:
Single Quotes: “ ' “
Literal storage of the string
Double Quotes: “ " “
Allows “interpretation”
escape sequences
values for imbedded variables (eg. $value)

12. Command line php can be used from a command line
Must be in a “path” or in the directory
Windows XAMPP:
Use the Shell button to set environment

13. Comments Scripts must be maintainable!!!! Single line: // or #
Use comments to document the code
Single line: // or #
echo “test1”;
echo “test2”; // this is a comment
echo “test3”; # this is another comment
One or more lines: /* … */
echo “test2”; /* this starts a comment
that continues on the next
line and ends here */
echo “test3”;

14. Variables - Names Variables Begin with a $ Second character may be:
a letter - or -
an underscore
Third and following characters may be:
letters
numbers
underscores
No practical length restriction

15. Variables - Types php is a weakly typed language
Do not need to declare variable type
Programmers responsibility to put and retrieve the correct type of data
php will convert data types as needed

16. Variables - Assigning Basic assignment operator is the =
$var1 = 255; // var1 is an integer
$var2 = “Test”; // var2 is a string
$var3 = 3.1; // var3 is a float
$var4 = TRUE; // var4 is a boolean

17. Variables: Interpolating
Interpolating variables in string
php will replace variables in strings with their values
String must be in double quotes
Example
$dogs = 2;
echo “There are $dogs in the yard.”;
Curly braces
will allow the variable to be parsed and placed exactly in text (no spaces)

18. Variable variables Variables may contain the name of variables!
Use $$varname to access
To use:
Declare your variables
$dogname = “Fido”;
$catname = “Felix”;
Assign variable name to your “variable variable”
$petname = “dogname”;
Use the “variable variable” – note the use of $$
echo “Your pet name is “, $$petname;
Example: ajkExamples/ch01/varvar.php

19. Constants php makes creating constants easy: define()
define(“pi”, );
define(“fname”, “Jack”);
define(“lname”, “Spratt”);

20. Keywords endif endswitch endwhile extends final (as of PHP 5) for
PHP Keywords
abstract
(as of PHP 5)
and
array() as
break
case
catch
cfunction
(PHP 4 only)
class clone
const
continue
declare
default do
else
elseif
enddeclare
endfor
endforeach
namespace
(as of PHP 5.3)
new
old_function
(PHP 4 only) or
private
(as of PHP 5)
protected
public
static
switch
throw
try
use
var
while
xor
endif
endswitch
endwhile
extends
final
(as of PHP 5)
for
foreach
function
global
goto
(as of PHP 5.3) if
implements
interface
instanceof

21. Keywords Compile-time constants Language constructs die()
__CLASS__ __DIR__
(as of PHP 5.3)
__FILE__
__FUNCTION__
__METHOD__
__NAMESPACE__
Language constructs
die()
echo()
empty()
exit()
eval()
include()
include_once()
isset()
list()
require()
require_once()
return()
print()
unset()

22. Data Types
Boolean
Integer
Float
String
Array
Object
Resourse
NULL