These are some basics you need to start with PHP, Any queries, get in touch!!

1. By Sanketkumar Biswas
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2. Client Server Arch.
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3. Server Side
Scripting
Generates dynamic web pages.
Practically invisible to end - user.
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4. Web Application
An application that runs within a web browser.
And can be accessed over a network.
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5. What is PHP ?
It is a server side scripting language used for
web development.
Created by Rasmus Lerdorf in 1995
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6. Why PHP ?
Open Source
Very good set of built in functions
Very good database support
Great support community
Many frameworks
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7. Getting started with PHP
<?php
echo "Hello World";
?>
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8. Including files
include('/filepath/filename/')
include_once('/filepath/filename/')
require('/filepath/filename/')
require_once('/filepath/filename/')
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9. PHP Syntax
PHP is programmer centric.
HTML and PHP are not same.
PHP is white space insensitive.
PHP is sometimes case sensitive.
Termination by semicolon (;)
Braces define blocks.
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10. Programmer Centric
Focuses on convenience for programmer.
Does not focus much on correctness.
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11. HTML Vs. PHP
HTML is client side.
PHP is server side.
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12. White space Insensitive
<?php
$val = 2 + 2; //single spaces
$val = 2 + 2; //spaces and tabs
$val =
2
+ 2; //multiple lines
?>
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13. Case Sensitive
<?php
$val = 20;
echo "variable value is $val";
echo "variable value is $VaL";
?>
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14. Case Sensitive
<?php
HELLO();
function hello() {
EcHo "Hello!!";
}
?>
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15. Termination
<?php
echo "Hello World";
?>
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16. Braces define block
<?php
if (1 == 1)
echo "Hello World";
if (1 == 1) {
echo "Hello ";
echo "World";
}
?> 16

17. Commenting
<?php
// this is a single line comment.
# this is also a single line comment.
/* this is a
multi line
comment. */
?>
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18. Variables
Variables are denoted with a leading ($) sign.
Value of variable is the most recent assignment.
Variable is assigned using (=) operator, to its left
is the variable and to right is the expression to
be evaluated.
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19. Variables can, but do not need to be declared
before assignment.
Variables have no type other than the type of its
current value.
Variables should always start with an alphabet.
Numerical values for a variable can be INT,
HEX, OCT, FLOAT and e.
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20. In variables for text we can use () as escape
character.
Boolean values is not case sensitive, TRUE,
TRuE, true, trUE, etc.
Prefix for HEX is "0x" and for OCT is "0".
Range of INT varies with respect to processor
bits, i.e. different for 32 and 64 bit processor.
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21. $x = 'Hello';
$x = "Hello";
$x = <<<var
Hello
var;
Single quotes display as it is, whereas double
quotes and heredoc do interpretation.
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22. Creating a variable
$x = 3;
Changing value
$x = $x + 5;
Changing value as well as type
$x = $x + 0.5;
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23. Global Variables:
$x = "HELLO";
function test() {
global $x;
return $x;
}
echo test();
Super Global Variables: $_POST, $_GET, etc.
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24. Outputting
echo "Hello World n Welcome to PHP";
echo "Hello World <br> Welcome to PHP";
echo "$var1 n $var2";
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25. Arrays
Creating arrays
$array = array(1, -2, 'cat', TRUE);
$array[] = 2.6;
$array[5] = 012;
$array[] = 0xA;
$array[7] = 5e2;
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26. Creating arrays with index
$array = array(
0 => 1,
1 => -2,
2 => 'cat',
3 => TRUE
);
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27. Creating arrays with string index
$array = array(
'INT' => 1,
'NINT' => -2,
'STRING' => 'cat',
'BOOLEAN' => TRUE
);
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28. Creating multi dimensionsl arrays
$array = array(
'INT' => array(
'POS' => 1,
'NEG' => -2
)
);
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29. Deleting arrays
unset($array[2]);
Unset is not the same as,
$array[2] = "";
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30. Iterating arrays
$array = array(
'INT' => 1, 'NINT' => -2, 'STRING' => 'cat'
);
foreach($array as $element) {
echo $element."<br>";
}
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31. Operators
Arithmetic > Comparison > Logical
Arithmetic: +, -, *, /, %
Comparison: ==, ===, !=, !==, ......
Logical: and, or, !, .......
break: used to stop loops.
continue: used to stop iteration.
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32. Arithmetic Operators
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33. Comparison Operators
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34. Logical Operators
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35. Constants
Defining a constant
define("CONSTANT_NAME","VALUE");
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36. Type Casting
$variable = (TYPE) VALUE;
$x = 5.5;
$y = (INT) $x; // $y = 5
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37. Functions
Declaration:
function NAME(ARG1, ARG2=DEFAULT);
Eg:
$x = "Hello";
function app($x,$s="World") {
return $x . $s;
}
$a = app($x); // HelloWorld
$b = app($y,"India"); // HelloIndia
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38. Some Important
Functions
strlen(): gives length of string.
strcmp(x,y): case sensitive string compare.
strcasecmp(x,y): case in sensitive string
compare.
strncmp(x,y,n): checks first n characters.
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39. strtoupper(x): converts to uppercase.
strtolower(x): converts to lowercase.
trim(x): removes white space.
substr(x,m,n): creates substring of x from m to n
characters.
ord(x): gives int value for character.
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40. count(x): gives no. Of elements in array.
isset(x): checks if has value.
sort(x): sorts array wrt values.
ksort(x): sorts array wrt keys.
array_merge(x,y): merge arrays to a new one.
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41. array_slice(x,m,n): creates a sub array of x from
m key to the next n keys.
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42. Branching
if... else...
if ($a > $b) {
$c = $a - $b;
echo $c;
} else {
$c = $b - $a;
echo $c;
} 42

43. switch
switch($a) {
case 1: echo "one"; break;
case 2: echo "two"; break;
case 3: echo "three"; break;
default: echo "no number"; break;
}
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44. Looping
while
$count = 1;
while ($count <= 10) {
echo "Count is $count n";
$count++;
}
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45. do - while
$count = 45;
do {
echo "Count is $count n";
$count++;
} while ($count <= 10);
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46. for
$limit = 5;
for($count=0; $count<$limit; $count++)
{
echo "Count is $count n";
}
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47. PHP and Forms
HTTP is a stateless protocol
Data is sent using
GET
POST
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48. To collect data for PHP processing we use super
global variables.
$_GET
$_POST
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49. PHP and MySQL
Initialise a database connection
mysql_connect('host','username','pass');
mysql_select_db('dbname');
Firing a query
mysql_query('Query');
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50. <?php
mysql_connect('localhost','root','');
mysql_select_db('demo');
$res = mysql_query('SELECT * FROM table');
while ($row = mysql_fetch_assoc($res))
{ echo $row['name']; }
?>
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51. Session
PHP Session variable is super global.
It has values of a single user across many pages
in an application.
It is located server side.
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52. Starting Session
session_start();
Session Variable
$_SESSION['username']
Destroying Session
session_destroy();
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53. Cookie
Cookie is also super global variable.
It is used to store information about user and its
visit on user's computer.
It is located client side.
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54. Setting cookie
setcookie('name','rohit',time()+(3600));
Cookie variable
$_COOKIE['name']
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55. Thank You
Follow me on:
Facebook: http://fb.com/sanketkumarbiswas/
Twitter: @sankeybiswas
LinkedIn: http://linkedin.com/in/sanketkumarbiswas/
Web: http://www.sankeybiswas.com/
Cell: +91 9820 477 377
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