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Beginners-Guide-To-PHP

Beginners Guide To PHP

What Is PHP?

PHP stands for Hypertext PreProcessor. It is a server-side scripting language. The PHP code can be mixed in with regular HTML tags and parsed on the server. PHP first showed up in the form of a set of Perl scripts that the creator, Rasmus Lerdorf, used to manage his online resume. Later, it was adapted by Andi Gutmans and Zeev Suraski in 1997 to use a C-written compiler. It was an entire remake of Lerdorf's that turned PHP into the web language we know today.

What Can PHP Be Used For?

PHP is used in the creation of dynamic web pages. It is popular among many web developers due to its fast parsing and flexibility. PHP is a popular tool for managing a form's data after it is submitted. It is also extremely versatile and comes built in with many different interfaces and API's. It has database capability built into the language, the most common database being MySQL. PHP can generally connect to any SQL enabled database.

What Is The Syntax Like?

PHP is similar in structure to Perl and C. You use curly braces { }, to define blocks of code, and the semi-colon to specify the end of a statement. If you are familiar with Perl, then you should have no difficulty learning PHP. It maintains all the traditional loops, if/else, and subroutines that are expected in a programming language. One difference you will note is that the code is ?embedded in with the HTML, but you can use a seperate file instead. The PHP code is differentiated from HTML code by use of the <?php and ?> opening and closing tags. These tell the server that when it finds a PHP file, to scan through for these tags, and execute the code in between them. The server recognizes a PHP enabled file by it's extension, .php. These are essentially HTML files with PHP code in them.

An Example PHP Program

This is an example of a PHP parsed web page.

<
?php   
// Specify title of page   
$title = 'PHP Test'; ?> 
<html>
<head>
<title> <?php echo "$title"; ?> </title>
</head>
<body>

<
?php   
// Create an array with each word of statement.   
$myArray = array('This', 'is', 'a', 'PHP', 'test.');   
// Loop through array and print each word   for ($i = 0; $i <
5; $i++) {     echo "$myArray[$i]"
;   
} ?> 
</body>
</html>

What Do I Need To Get Started?

PHP requires only a server with PHP installed and a simple ASCII text editor such as Notepad (standard on all Windows machines), or VI, eMacs, Kate, etc. for a UNIX/Linux machine. PHP can be downloaded here.

Common PHP Problems

PHP is case-sensitive, meaning that if you name a variable $MyVar, you cannot call it as $myvar or $mYvAr. Also, forgetting to close your curly braces. It helps to indent lines inside curly braces so that any missing braces can be spotted more easilly.

Are There Any PHP Tools I Can Buy?

You can find a variety of tools for download in the PHP Tools section

What Does Programmers Heaven Offer Me?

Visit the PHP section of the site to see articles on PHP as well as source code, developer tools and links to many sites, including tutorials pitched at many different levels. If you need assistance, why not post your question on our friendly and lively PHP message board.