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