Lecture Contains Basic syntax, Datatypes, Operators, Loops, Conditional Statement, Arrays, Function, Class and Objects, Inheritance, Interface Android App to learn PHP - https://play.google.com/store/apps/details?id=learn.apps.phpprogramming

1. Introduction to PhP
Ajay Khatri
Senior Assistant Professor
Acropolis Institute of Technology & Research
www.ajaykhatri.in
https://play.google.com/store/apps/details?id=learn.apps.phpprogramming

2. PHP stands for
PHP => PHP: Hypertext Preprocessor.
This confuses many people because the first word of
the acronym is the acronym. This type of acronym is
called a recursive acronym.
its original name Personal Home Page

3. What is PHP?
Loosely typed scripting language
Executed on the server
Commonly used to build web applications

4. Who uses PHP?
Yahoo!
Facebook
20+ million other domain names

5. Brief History

6. Personal Home Page /
Forms Interpreter
Created by Rasmus Lerdorf
PHP/FI 1.0 released in 1995
PHP/FI 2.0 released in 1997

7. PHP: Hypertext
Preprocessor
Created by Andi Gutmans and Zeev Suraski
PHP 3.0 released in 1998
PHP 4.4 released in 2005

8. PHP 5
New object model
PHP 5.0 released in 2004
PHP 5.3 released in 2009

9. Syntax

10. Hello World
<?php
// hello.php
echo 'Hello, VT Code Camp.';
?>

11. Variable Assignment
<?php
$hello = 'Hello, VT Code Camp.';
echo $hello;

12. One Line Comments
<?php
// A one line comment
# Another one line comment

13. Multi-Line Comments
<?php
/*
A multi-line comment
*/

14. DocBlock Comments
<?php
/**
* This function does nothing
*
* @param string $bar
* @return void
*/
function foo($bar) {}

15. Primitive Data Types
<?php
$isPhpProgrammer = true; // boolean
$howOldIsPhp = 15; // integer
$pi = 3.14; // float
$event = 'VT Code Camp'; // string
A string can hold letters, numbers, and special
characters and it can be as large as up to 2GB
(2147483647 bytes maximum)

16. Conditionals

17. If
<?php
if (true) {
echo 'Yes';
}

18. If-Then-Else
<?php
if (false) {
echo 'No';
} else {
echo 'Yes';
}

19. If-Then-Else-If
<?php
if (false) {
echo 'No';
} elseif (false) {
echo 'No';
} else {
echo 'Yes';
}

20. Switch
<?php
switch ('PHP') {
case 'Ruby':
echo 'No';
break;
case 'PHP':
echo 'Yes';
break;
}

21. Operators

22. Arithmetic
<?php
$a = 10;
$b = $a + 1; // 11
$c = $a - 1; // 9
$d = $a * 5; // 50
$e = $a / 2; // 5
$f = $a % 3; // 1

23. String Concatenation
<?php
$myString = 'foo' . 'bar'; // foobar
$myString .= 'baz'; // foobarbaz

24. Comparison

25. Equivalence
<?php
if (2 == 3) { echo 'No'; }
if (3 == '3') { echo 'Yes'; }
if (2 != 3) { echo 'Yes'; }

26. Identity
<?php
if (3 === '3') { echo 'No'; }
if (3 === 3) { echo 'Yes'; }
if (3 !== 4) { echo 'Yes'; }

27. Logical Operators
<?php
// NOT
if (!true) { echo 'No'; }
// AND
if (true && false) { echo 'No'; }
// OR
if (true || false) { echo 'No'; }

28. Strings & Interpolation

29. Literal Single Quotes
<?php
$x = 2;
echo 'I ate $x cookies.';
// I ate $x cookies.

30. Double Quotes
<?php
$x = 2;
echo "I ate $x cookies.";
// I ate 2 cookies.

31. Literal Double Quotes
<?php
$x = 2;
echo "I ate $x cookies.";
// I ate $x cookies.

32. Curly Brace
Double Quotes
<?php
$x = 2;
echo "I ate {$x} cookies.";
// I ate 2 cookies.

33. Constants

34. Defining
<?php
define('HELLO', 'Hello, Code Camp');
echo HELLO; // Hello, Code Camp

35. As of PHP 5.3
<?php
const HELLO = 'Hello, Code Camp';
echo HELLO; // Hello, Code Camp

36. Arrays

37. Automatic Indexing
<?php
$foo[] = 'bar'; // [0] => bar
$foo[] = 'baz'; // [1] => baz

38. Explicit Indexing
<?php
$foo[0] = 'bar'; // [0] => bar
$foo[1] = 'baz'; // [1] => baz

39. Array Construct with
Automatic Indexing
<?php
$foo = array(
'bar', // [0] => bar
'baz', // [1] => baz
);

40. Array Construct with
Explicit Indexing
<?php
$foo = array(
0 => 'bar', // [0] => bar
1 => 'baz', // [1] => baz
);

41. Array Construct with
Arbitrary Indexing
<?php
$foo = array(
1 => 'bar', // [1] => bar
2 => 'baz', // [2] => baz
);

42. Associative Array
Explicit Indexing
<?php
$foo['a'] = 'bar'; // [a] => bar
$foo['b'] = 'baz'; // [b] => baz

43. Associative Array
Array Construct
<?php
$foo = array(
'a' => 'bar', // [a] => bar
'b' => 'baz', // [b] => baz
);

44. http://ajaykhatri.inhttp://ajaykhatri.in
Reading, Writing, and
Appending Arrays
Arrays

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Associate values to keys
Keys can be integers (enumerative arrays) or
strings (associative arrays)
Values can be primitive types, objects, or
other arrays (multidimensional arrays)
Arrays

46. http://ajaykhatri.inhttp://ajaykhatri.in
<?php
$post = array(
'id' => 1234,
'title' => 'Intermediate PHP',
'updated' => new DateTime(
'2010-12-16T18:00:00-05:00'
),
'draft' => false,
'priority' => 0.8,
'categories' => array('PHP', 'BTV')
);

47. http://ajaykhatri.inhttp://ajaykhatri.in
<?php
$post = array(
'id' => 1234,
'title' => 'Intermediate PHP',
// …
);
echo $post['title']; // Intermediate PHP

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<?php
$post = array(
'id' => 1234,
'title' => 'Intermediate PHP',
// …
);
$post['title'] = 'PHP 201';

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<?php
$post = array(
'id' => 1234,
'title' => 'Intermediate PHP',
'updated' => new DateTime(
'2010-12-16T18:00:00-05:00'
),
'draft' => false,
'priority' => 0.8,
'categories' => array('PHP', 'BTV')
);
$post['summary'] = 'Arrays, functions, and
objects';

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<?php
$post = array(
// …
'categories' => array('PHP', 'BTV')
);
$post['categories'][] = 'Programming';
print_r($post['categories']);
/*
Array
(
[0] => PHP
[1] => BTV
[2] => Programming
)
*/

51. http://ajaykhatri.inhttp://ajaykhatri.in
<?php
$post = array(
// …
'categories' => array('PHP', 'BTV')
);
$post['categories'][1] = 'Burlington';
print_r($post['categories']);
/*
Array
(
[0] => PHP
[1] => Burlington
)
*/

52. Iterators

53. While
<?php
$x = 0;
while ($x < 5) {
echo '.';
$x++;
}

54. For
<?php
for ($x = 0; $x < 5; $x++) {
echo '.';
}

55. Foreach
<?php
$x = array(0, 1, 2, 3, 4);
foreach ($x as $y) {
echo $y;
}

56. Foreach Key/Value Pairs
<?php
$talks = array(
'php' => 'Intro to PHP',
'ruby' => 'Intro to Ruby',
);
foreach ($talks as $id => $name) {
echo "$name is talk ID $id.";
echo PHP_EOL;
}

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Array Key Exists,
In Array, and Array Keys

58. http://ajaykhatri.inhttp://ajaykhatri.in
<?php
$post = array(
'id' => 1234,
// …
'categories' => array('PHP', 'BTV')
);
if (array_key_exists('categories', $post))
{
echo implode(', ', $post['categories']);
} else {
echo 'Uncategorized';
}

59. http://ajaykhatri.inhttp://ajaykhatri.in
<?php
$post = array(
// …
'categories' => array('PHP', 'BTV')
);
if (in_array('PHP', $post['categories'])) {
echo 'PHP: Hypertext Preprocessor';
}

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<?php
$posts = array(
1233 => array(/* … */),
1234 => array(/* … */),
);
print_r(array_keys($posts));
/*
Array
(
[0] => 1233
[1] => 1234
)
*/

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Sorting Arrays

62. http://ajaykhatri.inhttp://ajaykhatri.in
<?php
$post = array(
// …
'categories' => array('PHP', 'BTV')
);
sort($post['categories']);
print_r($post['categories']);
/*
Array
(
[0] => BTV
[1] => PHP
)
*/

63. http://ajaykhatri.inhttp://ajaykhatri.in
Sorting Arrays
sort() - ascending order
rsort() - descending order
asort() - according to the value
ksort() - according to the key
arsort() - descending order, according
to the value
krsort() - descending order, according
to the key

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Array Push and
Array Pop (stack)

65. http://ajaykhatri.inhttp://ajaykhatri.in
<?php
$post = array(
// …
'categories' => array('PHP')
);
array_push($post['categories'], 'BTV');
echo array_pop($post['categories']);
// BTV
print_r($post['categories']);
/*
Array
(
[0] => PHP
)
*/

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Array Unshift and
Array Pop (queue)

67. http://ajaykhatri.inhttp://ajaykhatri.in
<?php
$post = array(
// …
'categories' => array('BTV')
);
array_unshift($post['categories'], 'PHP');
print_r($post['categories']);
/*
Array
(
[0] => PHP
[1] => BTV
)
*/
echo array_pop($post['categories']);
// BTV

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Iterating Over Arrays

69. http://ajaykhatri.inhttp://ajaykhatri.in
<?php
$post = array(
// …
'categories' => array('PHP', 'BTV')
);
foreach ($post['categories'] as $v) {
echo $v . PHP_EOL;
}
/*
PHP
BTV
*/

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<?php
$post = array(
// …
'categories' => array('PHP', 'BTV')
);
foreach ($post['categories'] as $k => $v) {
echo $k . ': ' . $v . PHP_EOL;
}
/*
0: PHP
1: BTV
*/

71. http://ajaykhatri.inhttp://ajaykhatri.in
<?php
$post = array(
'id' => 1234,
'title' => 'Intermediate PHP',
// …
);
foreach ($post as $k => $v) {
echo $k . ': ' . $v . PHP_EOL;
}
/*
id: 1234
title: Intermediate PHP
…
*/

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Implode and Explode

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Implode Function
join elements of an array with a string
implode (separator, array)
Implode Function
Split a string by a specified string into
pieces (into an array)
explode (separator,string,limit)

74. http://ajaykhatri.inhttp://ajaykhatri.in
<?php
$post = array(
// …
'categories' => array('PHP', 'BTV')
);
echo implode(', ', $post['categories']);
// PHP, BTV
join elements of an array with a string
implode (separator, array)

75. http://ajaykhatri.inhttp://ajaykhatri.in
<?php
$post = array(
// …
'categories' =>
explode(', ', 'PHP, BTV')
);
print_r($post['categories']);
/*
Array
(
[0] => PHP
[1] => BTV
)
*/

76. http://ajaykhatri.inhttp://ajaykhatri.in
<?php
print_r(get_defined_functions());
/*
Array
(
[internal] => Array
(
[0] => zend_version
[1] => func_num_args
// …
)
[user] => Array
(
)
)
*/

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<?php
$functions = get_defined_functions();
echo count($functions['internal']);
// 1857

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<?php
$name = 'Marcus Börger';
if (function_exists('mb_strtolower')) {
echo mb_strtolower($name, 'UTF-8');
// marcus börger
} else {
echo strtolower($name);
// marcus b?rger
}

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Functions

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Built-in
<?php
echo strlen('Hello'); // 5
echo trim(' Hello '); // Hello
echo count(array(0, 1, 2, 3)); // 4
echo uniqid(); // 4c8a6660519d5
echo mt_rand(0, 9); // 3
echo serialize(42); // i:42;
echo json_encode(array('a' => 'b'));
// {"a":"b"}

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User-Defined Functions

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Rules
Any valid PHP code is allowed inside
functions, including other functions and class
definitions
Function names are case-insensitive
Once defined, a function cannot be undefined

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User-Defined
<?php
function add($x, $y)
{
return $x + $y;
}
echo add(2, 4); // 6

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Anonymous Functions
<?php
$sayHi = function ()
{
return 'Hi';
};
echo $sayHi(); // Hi

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Multiple Arguments

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<?php
function isPublished(DateTime $published,
$draft)
{
if ($draft) { return false; }
$now = new DateTime();
return $now >= $published;
}
$published = new
DateTime('2010-12-16T18:00:00-05:00');
$draft = false;
var_dump(isPublished($published, $draft));
// bool(true)

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Default Arguments

88. http://ajaykhatri.inhttp://ajaykhatri.in
<?php
function isPublished(DateTime $published,
$draft, $now = false)
{
if ($draft) { return false; }
$now = $now ? $now : new DateTime();
return $now >= $published;
}
$published = new
DateTime('2010-12-16T18:00:00-05:00');
$draft = false;
$now = new
DateTime('2010-12-16T17:59:59-05:00');
var_dump(isPublished($published, $draft,
$now));
// bool(false)

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Function Overloading
(not really)

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<?php
function nextId($arg1)
{
switch (true) {
case is_array($arg1):
return max(array_keys($arg1)) + 1;
case is_int($arg1):
return $arg1 + 1;
}
}
$posts = array(
1233 => array(/* … */),
1234 => array(/* … */),
);
echo nextId($posts); // 1235
echo nextId(1234); // 1235

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Variable Number of
Arguments

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<?php
function mostRecent()
{
$max = false;
foreach (func_get_args() as $arg) {
$max = $arg > $max ? $arg : $max;
}
return $max;
}
$mostRecent = mostRecent(
new DateTime('2010-12-14T18:00:00'),
new DateTime('2010-12-16T18:00:00'),
new DateTime('2010-12-15T18:00:00')
);
// 2010-12-16T18:00:00

93. http://ajaykhatri.inhttp://ajaykhatri.in
Learn PHP using
Android App
https://play.google.com/store/apps/details?id=learn.apps.phpprogramming

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Classes & Objects - PhP
Ajay Khatri
Senior Assistant Professor
Acropolis Institute of Technology & Research
www.ajaykhatri.in
https://play.google.com/store/apps/details?id=learn.apps.phpprogramming

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Classes & Objects

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Class Declaration
<?php
class Car
{
}

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Property Declaration
<?php
class Car
{
private $_hasSunroof = true;
}

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Method Declaration
<?php
class Car
{
public function hasSunroof()
{
return $this->_hasSunroof;
}
}

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Class Constants
<?php
class Car
{
const ENGINE_V4 = 'V4';
const ENGINE_V6 = 'V6';
const ENGINE_V8 = 'V8';
}
echo Car::ENGINE_V6; // V6

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Object Instantiation
& Member Access
<?php
$myCar = new Car();
if ($myCar->hasSunroof()) {
echo 'Yay!';
}

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Class Inheritance
<?php
class Chevy extends Car
{
}

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Member Visibility

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Public
Default visibility
Visible everywhere

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Protected
Visible to child classes
Visible to the object itself
Visible to other objects of the same type

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Private
Visible to the object itself
Visible within the defining class declaration

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Objects

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Basics
Encapsulate metadata and behavior
metadata => properties (variables, constants)
behavior => methods (functions)

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Anonymous Objects

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Cast an Associative
Array to (object)
<?php
$a = array(
'foo' => 'bar',
);
$o = (object) $a;
echo $o->foo; // 'bar'

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stdClass
$o = new stdClass;
$o->foo = 'bar';
echo $o->foo; // 'bar'

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Declaring a Class
<?php
class Foo
{
}

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Declaring Properties
<?php
class Foo
{
protected $bar = 'bar';
}

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Extending Classes
<?php
class FooBar extends Foo
{
}

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Modifiers
final: cannot be overridden in extending
classes
abstract: must be overridden in extending
classes

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Abstract Classes

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<?php
abstract class AbstractFoo
{
abstract public function sayBar();
}
class Foo extends AbstractFoo
{
public $bar;
public function sayBar()
{
echo $this->bar;
}
}

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Interfaces
"Blueprints" for classes
Typically indicate behaviors found in
implementing classes
You can implement many interfaces, but only
extend once
Allows you to compose multiple behaviors
into a single class

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Interfaces
<?php
interface Vehicle
{
public function hasSunroof();
}

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Implementing Interfaces
<?php
class Car implements Vehicle
{
public function hasSunroof()
{
return $this->_hasSunroof;
}
}

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<?php
interface Resource {
public function getResource();
}
interface Dispatcher {
public function dispatch();
}
abstract class DispatchableResource
implements Resource,Dispatcher
{
// …
}

121. http://ajaykhatri.inhttp://ajaykhatri.in
<?php
interface Resource { /* … */ }
interface Dispatcher { /* … */ }
abstract class DispatchableResource
implements Resource,Dispatcher
{
protected $resource;
public function getResource() {
return $this->resource;
}
public function dispatch() {
return 'Dispatched ' . $this-
>getResource();
}
}

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<?php
interface Resource { /* … */ }
interface Dispatcher { /* … */ }
abstract class DispatchableResource
implements Resource,Dispatcher { /* … */ }
class TrafficCop extends
DispatchableResource
{
protected $resource = 'traffic cop';
}
$cop = new TrafficCop();
echo $cop->dispatch();
// 'Dispatched traffic cop'

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Construct, Destruct, and
Invoke
__construct— Constructor (used when
"new Class" is called)
__destruct— Destructor (called when
object is destroyed)
__invoke— Call an object instance like a
function (echo $object();)

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Tools

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IDEs
Eclipse (PDT, Zend Studio, Aptana)
NetBeans
PHPStorm
Emacs
Vim
Many more…

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Frameworks
Zend Framework
Symfony
CodeIgniter
Agavi
CakePHP
Many more…

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Learn PHP using
Android App
https://play.google.com/store/apps/details?id=learn.apps.phpprogramming

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Questions?