Post on 10-May-2015
PHP Intermediate
Jamshid HashimiTrainer, Cresco Solution
http://www.jamshidhashimi.com jamshid@netlinks.af @jamshidhashimi ajamshidhashimi
Afghanistan Workforce Development Program
Agenda
• Arrays• Loop– For statement– Foreach statement– While statement– Do While statement
• PHP Functions• Get & Post Variable• Difference between PHP 4 & PHP 5• Exercise!
Arrays
• An array is a special variable, which can hold more than one value at a time.
• array — Create an array
• Multidimensional Arrays
$arr = array("a" => "orange", "b" => "banana", "c" => "apple");
$fruits = array ( "fruits" => array("a" => "orange", "b" => "banana", "c" => "apple"), "numbers" => array(1, 2, 3, 4, 5, 6), "holes" => array("first", 5 => "second", "third"));
Arrays: count()
• count — Count all elements in an array, or something in an object
$arr = array("Kabul", "Balkh", "Herat", "Qandahar");echo count($arr);> 4
Arrays: array_slice()
• array_slice — Extract a slice of the array
$arr = array("Kabul", "Balkh", "Herat", "Qandahar");$new_arr = array_slice($arr,1,2);print_r($new_arr);> Array ( [0] => Balkh [1] => Herat )
Arrays: array_reverse()
• array_reverse — Return an array with elements in reverse order
$arr = array("Kabul", "Balkh", "Herat", "Qandahar");$new_arr = array_reverse($arr);print_r($new_arr);> Array ( [0] => Qandahar [1] => Herat [2] => Balkh [3] => Kabul )
Arrays: array_keys()
• array_keys — Return all the keys or a subset of the keys of an array
$arr = array("Kabul", "Balkh", "Herat", "Qandahar");$new_arr = array_keys($arr);print_r($new_arr);> Array ( [0] => 0 [1] => 1 [2] => 2 [3] => 3 )
Arrays: in_array()
• in_array — Checks if a value exists in an array
$arr = array("Kabul", "Balkh", "Herat", "Qandahar");
if(in_array("Kabul",$arr)){ echo "Found";}else{ echo "Not Found";}> Found
Arrays: is_array()
• is_array — Finds whether a variable is an array
$arr = array("Kabul", "Balkh", "Herat", "Qandahar");
if(is_array($arr)){ echo "YES";}else{ echo "NO";}> YES
Arrays: shuffle()
• shuffle — Shuffle an array
$arr = array("Kabul", "Balkh", "Herat", "Qandahar");shuffle($arr);print_r($arr);
> Array ( [0] => Balkh [1] => Herat [2] => Qandahar [3] => Kabul ) > Array ( [0] => Herat [1] => Qandahar [2] => Kabul [3] => Balkh ) > ….
Arrays: array_unique()
• array_unique — Removes duplicate values from an array
$arr = array("Kabul", "Balkh", "Herat", "Qandahar","Kabul");$new_arr = array_unique($arr);print_r($new_arr);> Array ( [0] => Kabul [1] => Balkh [2] => Herat [3] => Qandahar )
LOOPS
• In computer programming, a loop is a sequence of instructions that is continually repeated until a certain condition is reached.
• An infinite loop is one that lacks a functioning exit routine . The result is that the loop repeats continually until the operating system senses it and terminates the program with an error or until some other event occurs (such as having the program automatically terminate after a certain duration of time).
LOOPS
• for – Syntax
• foreach - Syntax
for (init; condition; increment){
code to be executed;}
foreach ($array as $value){
code to be executed;}
LOOPS
• while – Syntax
• do-while – Syntax
while (condition){
code to be executed;}
do{
code to be executed;}while (condition);
PHP Functions
• The real power of PHP comes from its functions.
• In PHP, there are more than 700 built-in functions.
• A function will be executed by a call to the function.
• You may call a function from anywhere within a page.
PHP Functions: Syntax
• PHP function guidelines:– Give the function a name that reflects what the
function does– The function name can start with a letter or
underscore (not a number)
function functionName(){
code to be executed;}
PHP Functions: Sample<html><body>
<?phpfunction writeName(){echo “Ahmad Mohammad Salih";}
echo "My name is ";writeName();?>
</body></html>
PHP Functions - Adding parameters
• To add more functionality to a function, we can add parameters. A parameter is just like a variable.
• Parameters are specified after the function name, inside the parentheses.
PHP Functions – Sample 2<html><body>
<?phpfunction writeName($fname){echo $fname . " Ahmadi.<br>";}
echo "My name is ";writeName(“Ahmad");echo "My sister's name is ";writeName(“Saliha");echo "My brother's name is ";writeName(“Mohammad");?>
</body></html>
PHP Functions - Return values
• To let a function return a value, use the return statement.
<html><body><?phpfunction add($x,$y){$total=$x+$y;return $total;}echo "1 + 16 = " . add(1,16);?></body></html>
POST & GET
• GET requests can be cached• GET requests remain in the browser history• GET requests can be bookmarked• GET requests should never be used when dealing
with sensitive data• GET requests have length restrictions– 1,024 characters is a safe upper limit
• GET requests should be used only to retrieve data
POST & GET
• POST requests are never cached• POST requests do not remain in the browser
history• POST requests cannot be bookmarked• POST requests have no restrictions on data
length
POST & GET
<form action=”” method=”get”>
<form action=”” method=”post”>
Difference between PHP4 & PHP5
• PHP4 was powered by Zend Engine 1.0, while PHP5 was powered by Zend Engine II.
• PHP4 is more of a procedure language while PHP5 is object oriented.
• In PHP5 one can declare a class as Abstract.• PHP5 incorporates static methods and
properties.• PHP5 introduces a special function called
__autoload()
Difference between PHP4 & PHP5
• In PHP5, there are 3 levels of visibilities: Public, private and protected.
• PHP5 introduced exceptions.• In PHP4, everything was passed by value,
including objects. Whereas in PHP5, all objects are passed by reference.
• PHP5 introduces interfaces. All the methods defined in an interface must be public.
• PHP5 introduces new functions.
Difference between PHP4 & PHP5
• PHP5 introduces some new reserved keywords.• PHP5 includes additional OOP concepts than
php4, like access specifiers , inheritance etc.• PHP5 includes reduced consumption of RAM.• PHP5 introduces increased security against
exploitation of vulnerabilities in PHP scripts.• PHP5 introduces easier programming through
new functions and extensions.
Difference between PHP4 & PHP5
• PHP5 introduces a brand new built-in SOAP extension for interoperability with Web Services.
• PHP5 introduces a new SimpleXML extension for easily accessing and manipulating XML as PHP objects.
Exercise!
• Write a program which reverse the order of the given string
• Write a function which returns the sum of all elements in a given integer array.
• Write a program which returns the middle element of a given array
• Write a program which find the duplicates of a given array and return both the duplicate values and the new duplicate-free array.
Exercise!
• Find the biggest item of an integer array (Without using any built-in function e.g. max())
• Write a program that check if a given program is palindrome or not
• Write a function which takes an array (key=>value formatted) as a parameter and outputs the keys and values in separate columns of a table.
Key value
Exercise!
• A factorial of any given integer, n, is the product of all positive integers between 1 and n inclu-sive. So the factorial of 4 is 1 × 2 × 3 × 4 = 24, and the factorial of 5 is 1 × 2 × 3 × 4 × 5 = 120. This can be expressed recursively as follows: – If n == 0, return 1. (This is the base case) – If n > 0, compute the factorial of n–1, multiply it by n,
and return the resultWrite a PHP script that uses a recursive function to display the factorials of a given number.
QUESTIONS?