PHP Execution

8/3/2019 PHP Execution

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PHP DEMO



How to run PHP files on

localhost? 1. First download the xampp from

http://www.apachefriends.org/en/xampp.html

2. Extract the file and double click the exe.This will install Mysql and Apache servers.







Cont..

3. Once the installation is complete, you will findXAMPP under Start / Programs / XAMPP.

4. You can use the XAMPP Control Panel to start/stopall servers. Start Mysql and Apache servers.

5. C:/Program Files/XAMPP/htdocs/

6. To run the php file, you just need to browsehttp://localhost/test.php



C-like language

Free format - white space is ignored.

Statements are terminated by semi-colon ;

Statements grouped by { … }

Comments begin with // or a set of comments /* */



Continue..

Assignment is ‘=’: $a=6

Relational operators are ,< , > == ( not a singleequal)

Control structures include if (cond) {..} else { },

while (cond) { .. } , for(startcond; increment;endcond) { }



Continue..

Functions are called with the name followed byarguments in a fixed order enclosed in ( ) :substr(“fred”,0,2)

Case sensitive - $fred is a different variable to$FRED

Arrays are accessed with [ ] : $x[4] is the 5thelement of the array $x – indexes start at 0



Demo

Example script

<? PHP ……..?>

<script language="PHP">

</script>



Comments

PHP allows a couple of additional ways to create

comments. <?php

phpinfo(); # This is a built-in function

?> Multiple line comments. <?php

/*A script that gets information about the

PHP version being used.

*/

<? phpinfo(); ?>



If Use Improper Syntax

Suppose you use the wrong syntax:

<?php

print ( “A simple initialscript);

?>



A Little About PHP's Syntax

Some PHP Syntax Issues:

Be careful to use quotation marks, parentheses, and

brackets in pairs.

Most PHP commands end with a semicolon (;).

Be careful of case.

PHP ignores blank spaces.



OOModel

Procedural language

Extensive Function Library

Not fully object-oriented Java is fully object oriented – all functions have to be

in a class

In PHP, classes are additional but quite simple to use



DECLARING A CLASS

class MyClass {

... // List of methods

...

... // List of properties

...

}



Constructor

Unified constructor name __construct().

Instead of the constructor being the name of the class,

it is now declared as __construct

class MyClass

{

function __construct() {print "Inside constructor";

}

}



Destructor

Object destructor support by defining a__destructor() method.

Allows defining a destructor function thatruns when an object is destroyed:

class MyClass {

function __destruct() {

print ”Destroying object”; }

}



Class constants

Class constants.

Class definition can now include constantvalues.

using the class:

class MyClass {

const SUCCESS = "Success";

const FAILURE = "Failure";}

print MyClass::SUCCESS;



Interfaces

Gives the ability for a class to fulfill more than one is-arelationships. A class can inherit only from one class, butmay implement as many interfaces as it wants:

interface Display {function display();

}

class Circle implements Display {

function display() {print "Displaying circle\n";

}

}



Instanceof

instanceof operator.

Language-level support for is-a relationship

checking.

if ($obj instanceof Circle) {

print '$obj is a Circle';}



Final methods

The final keyword allows you to markmethods so that an inheriting class cannotoverload them.

class MyClass {

final function getBaseClassName() {

return __CLASS__;

}

}



Final classes.

After declaring a class as final It cannot beinherited.

final class FinalClass {}

class BogusClass extends FinalClass {}



Array

An array in PHP is a collection of key/valuepairs. This means that it maps keys (orindexes) to values.

Array indexes can be either integers orstrings

whereas values can be of any type (includingother arrays).



array()

Arrays can be declared using the array()construct.

Language construct, which generally takesthe following form (elements inside squarebrackets, [], are optional):

Syntax:

array([key =>] value, [key =>] value, ..)



Array Example

array(1, 2, 3) is the same as the more explicitarray(0 => 1, 1 => 2, 2 => 3).

☞

array("name" => "John", "age" => 28)☞ array(1 => "ONE", "TWO", "THREE") is

equivalent to array(1 => "ONE", 2 =>

"TWO", 3 => "THREE").

☞ array() an empty array



nested array() statement:

array(array("name" => "John", "age" => 28),

array("name" => "Barbara", "age" => 67))



OPERATORS

PHP contains three types of operators:unary operators, binary operators, and

one ternary operator. Binary operators are used on two

operands: 2 + 3 14 * 3.1415 $i – 1



Cont…

These examples are also simple examples of expressions.

PHP can only perform binary operations on

two operands that have the same type. However, if the two operands have different

types, PHP automatically converts one of

them to the other’s type, according to thefollowing rules

(unless stated differently, such as in theconcatenation operator).



Queries?

Any Questions

www.php.net

Community

www.phpbuilder.com: articles on PHP, discussionforums

Newsgroups

comp.lang.php

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