Library tutorials & articles

An Introduction to PHP

Getting Started

PHP scripts have the extension .php. The PHP script is placed between the <?php and ?> delimiters. The script that is placed between these delimiters is interpreted on the server into HMTL, before being sent to the client. The client will receive a pure HTML page.

Comments

You can comment your code using C++ type comments. The following shows the syntax for inline comments (a comment on a single line), and block comments (comments placed over several lines).

// This is an inline comment
/*
This is a block comment
placed over two or more
lines
*/

Output

There are two basic statements to output text with PHP, either using echo, or print.

Output Using echo

The text to be outputed follows the echo statement.

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN"
"http://www.w3.org/TR/html4/strict.dtd">
<html>
<head>
  <title>Starting PHP</title>
  <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
</head>
<body>
<p>
  <?php echo "Hello World<br>"; ?>
</p>
</body>
</html>

Output using print

The text to be outputed follows the print statement.

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN"
"http://www.w3.org/TR/html4/strict.dtd">
<html>
<head>
  <title>Starting PHP</title>
  <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
</head>
<body>
<p>
  <?php print "Hello World<br>"; ?>
</p>
</body>
</html>

PHP also offers a shothand way of outputting information, using the <?= and ?> delimiters. The following example prints the variable $name (passed from a form) to greet a user.

Hello <?=$name?>

PHP Information

The phpinfo function is useful for trouble shooting, providing the version of PHP, and how it is configured.

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN"
"http://www.w3.org/TR/html4/strict.dtd">
<html>
<head>
  <title>PHP Information</title>
  <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
</head>
<body>
<p>
  <?php phpinfo();?>
</p>
</body>
</html>

Comments

  1. 28 May 2009 at 22:12

    It is not just talk though: Zend server is flourishing despite the recession - "the Q1 of 2009 has been our strongest quarter ever," says Suraski - and although PHP's enterprise market share is small compared to Java or .NET, it is growing. Read more on ITJOBLOG.

  2. 02 Jan 2007 at 06:39
    Here they show how to send valued in one file to another(both are in same folder)
    but i need to send values in one folder to another


  3. 04 Apr 2006 at 10:20

    Yes, I think you're correct, although you could easily have a line like this:

    $num = $_POST['num'];


    to get around that problem. Which I think is what's missing from this tutorial Wink [;)]





  4. 04 Apr 2006 at 09:47

    In the PHP file should it be "$_POST["num"]" ?

    instead of just $num?

  5. 21 Feb 2004 at 04:09
    hello

    I have in php a header which brings a save as box , but when file is down loaded it contains the 6 blank spaces at the start of of document .
    I have to avoid storing these blank spaces.Please help me to solve this problem.
  6. 28 Jan 2004 at 15:16

    You can also do string concatenation like

    Code:

    $h = "Hello";
    $w = "World";


    $message = "$h $w";


  7. 01 Jan 1999 at 00:00

    This thread is for discussions of An Introduction to PHP.

Leave a comment

Sign in or Join us (it's free).

Gez Lemon I'm available for contract work. Please visit Juicify for details.

Related discussion

Related podcasts

  • EarthClassMail.com - Moving from LAMP to .NET 3.5

    Scott chats with Matt Davis, architect at EarthClassMail.com, about their move from a LAMP stack (Linux/Apache/mysql/PHP) to .NET 3.5. What's working, what's not, and what kinds of issues are they running into as their architect their solution.

Events coming up

  • Dec 3

    The Auckland PHP December meetup

    Auckland, New Zealand

    Topic: Magento E-Commerce platform Speaker: Robert Popovic, LERO9, Robert is the Technical Director and co-founder of LERO9. Robert attended the Electrotechnical Faculty at The University of Belgrade where he graduated with a Masters in Computer Science and Information Technology. Robert has worked exclusively in the field of web and software development throughout his career.

Want to stay in touch with what's going on? Follow us on twitter!