• PHP is an acronym for "PHP: Hypertext Preprocessor"
• PHP is a widely-used, open source scripting language
• PHP scripts are executed on the server
• PHP is free to download and use
What is a PHP File?
• PHP files can contain text, HTML, CSS, JavaScript, and PHP code
• PHP code are executed on the server, and the result is returned to the browser
as plain HTML
• PHP files have extension ".php"
What Can PHP Do?
• PHP can generate dynamic page content
• PHP can create, open, read, write, delete, and close files on the server
• PHP can collect form data
• PHP can send and receive cookies
• PHP can add, delete, modify data in your database
• PHP can be used to control user-access
• PHP can encrypt data
With PHP you are not limited to output HTML. You can output images, PDF files, and
even Flash movies. You can also output any text, such as XHTML and XML.
Why PHP?
• PHP runs on various platforms (Windows, Linux, Unix, Mac OS X, etc.)
• PHP is compatible with almost all servers used today (Apache, IIS, etc.)
• PHP supports a wide range of databases
• PHP is free. Download it from the official PHP resource: www.php.net
• PHP is easy to learn and runs efficiently on the server side
To start using PHP, you can:
• Find a web host with PHP and MySQL support
• Install a web server on your own PC, and then install PHP and MySQL
Use a Web Host with PHP Support
• If your server has activated support for PHP you do not need to do anything.
• Just create some .php files, place them in your web directory, and the server will
automatically parse them for you.
• You do not need to compile anything or install any extra tools.
• Because PHP is free, most web hosts offer PHP support.
• Set Up PHP on Your Own PC
,However, if your server does not support PHP, you must:
• install a web server
• install PHP
• install a database, such as MySQL
4.2 PHP Scripts
Basic PHP Syntax
• A PHP script can be placed anywhere in the document.
• A PHP script starts with <?php and ends with ?>:
<?php
// PHP code goes
here ?>
Example
<html>
<body>
<h1>My first PHP page</h1>
<?php
echo "Hello World!";
?>
</body>
</html>
• PHP statements end with a semicolon (;)
Comments in PHP
A comment in PHP code is a line that is not read/executed as part of the program. Its
only purpose is to be read by someone who is looking at the code.
Comments can be used to:
• Let others understand what you are doing
• Remind yourself of what you did - Most programmers have experienced coming
back to their own work a year or two later and having to re-figure out what they
did. Comments can remind you of what you were thinking when you wrote the
code
,Example
<html>
<body>
<?php
// This is a single-line comment
# This is also a single-line
comment /*
This is a multiple-lines comment
block that spans over multiple
lines
*/
// You can also use comments to leave out parts of a code line
$x = 5 /* + 15 */ + 5;
echo
$x; ?>
</body>
</html>
Example
<html>
<body>
<?php
ECHO "Hello World!<br>";
echo "Hello World!<br>";
EcHo "Hello World!<br>";
?>
</body>
</html>
In the example below, only the first statement will display the value of the $color
variable (this is because $color, $COLOR, and $coLOR are treated as three different
variables):
Example
<html>
<body>
<?php
$color = "red";
echo "My car is " . $color . "<br>";
echo "My house is " . $COLOR .
"<br>"; echo "My boat is " . $coLOR .
"<br>"; ?>
, </body>
</html>
4.3 Data Types
• Variables can store data of different types, and different data types can do
different things.
PHP supports the following data types:
• String
• Integer
• Float (floating point numbers - also called double)
• Boolean
• Array
• Object
• NULL
• Resource
PHP String
• A string is a sequence of characters, like "Hello world!".
• A string can be any text inside quotes. You can use single or double quotes:
Example
<html>
<body>
<?php
$x = "Hello world!";
$y = 'Hello world!';
echo $x;
echo "<br>";
echo $y;
?>
</body>
</html>
OUTPUT:
Hello world!
Hello world!
• PHP is a widely-used, open source scripting language
• PHP scripts are executed on the server
• PHP is free to download and use
What is a PHP File?
• PHP files can contain text, HTML, CSS, JavaScript, and PHP code
• PHP code are executed on the server, and the result is returned to the browser
as plain HTML
• PHP files have extension ".php"
What Can PHP Do?
• PHP can generate dynamic page content
• PHP can create, open, read, write, delete, and close files on the server
• PHP can collect form data
• PHP can send and receive cookies
• PHP can add, delete, modify data in your database
• PHP can be used to control user-access
• PHP can encrypt data
With PHP you are not limited to output HTML. You can output images, PDF files, and
even Flash movies. You can also output any text, such as XHTML and XML.
Why PHP?
• PHP runs on various platforms (Windows, Linux, Unix, Mac OS X, etc.)
• PHP is compatible with almost all servers used today (Apache, IIS, etc.)
• PHP supports a wide range of databases
• PHP is free. Download it from the official PHP resource: www.php.net
• PHP is easy to learn and runs efficiently on the server side
To start using PHP, you can:
• Find a web host with PHP and MySQL support
• Install a web server on your own PC, and then install PHP and MySQL
Use a Web Host with PHP Support
• If your server has activated support for PHP you do not need to do anything.
• Just create some .php files, place them in your web directory, and the server will
automatically parse them for you.
• You do not need to compile anything or install any extra tools.
• Because PHP is free, most web hosts offer PHP support.
• Set Up PHP on Your Own PC
,However, if your server does not support PHP, you must:
• install a web server
• install PHP
• install a database, such as MySQL
4.2 PHP Scripts
Basic PHP Syntax
• A PHP script can be placed anywhere in the document.
• A PHP script starts with <?php and ends with ?>:
<?php
// PHP code goes
here ?>
Example
<html>
<body>
<h1>My first PHP page</h1>
<?php
echo "Hello World!";
?>
</body>
</html>
• PHP statements end with a semicolon (;)
Comments in PHP
A comment in PHP code is a line that is not read/executed as part of the program. Its
only purpose is to be read by someone who is looking at the code.
Comments can be used to:
• Let others understand what you are doing
• Remind yourself of what you did - Most programmers have experienced coming
back to their own work a year or two later and having to re-figure out what they
did. Comments can remind you of what you were thinking when you wrote the
code
,Example
<html>
<body>
<?php
// This is a single-line comment
# This is also a single-line
comment /*
This is a multiple-lines comment
block that spans over multiple
lines
*/
// You can also use comments to leave out parts of a code line
$x = 5 /* + 15 */ + 5;
echo
$x; ?>
</body>
</html>
Example
<html>
<body>
<?php
ECHO "Hello World!<br>";
echo "Hello World!<br>";
EcHo "Hello World!<br>";
?>
</body>
</html>
In the example below, only the first statement will display the value of the $color
variable (this is because $color, $COLOR, and $coLOR are treated as three different
variables):
Example
<html>
<body>
<?php
$color = "red";
echo "My car is " . $color . "<br>";
echo "My house is " . $COLOR .
"<br>"; echo "My boat is " . $coLOR .
"<br>"; ?>
, </body>
</html>
4.3 Data Types
• Variables can store data of different types, and different data types can do
different things.
PHP supports the following data types:
• String
• Integer
• Float (floating point numbers - also called double)
• Boolean
• Array
• Object
• NULL
• Resource
PHP String
• A string is a sequence of characters, like "Hello world!".
• A string can be any text inside quotes. You can use single or double quotes:
Example
<html>
<body>
<?php
$x = "Hello world!";
$y = 'Hello world!';
echo $x;
echo "<br>";
echo $y;
?>
</body>
</html>
OUTPUT:
Hello world!
Hello world!
