PHP Syntax
Basic PHP Syntax
A PHP script is executed on the server, and the plain HTML result is sent back to the browser.
A PHP script can be placed anywhere in the document.
A PHP script starts with <?php and ends with
?>:
<?php
// PHP code goes here
?>The default file extension for PHP files is .php.
A PHP file normally contains some HTML tags and some PHP scripting code.
Below, we have an example of a simple PHP file, with a PHP script that uses
the PHP echo function to output some text
on a web page:
Example
A simple .php file with both HTML code and PHP code:
<!DOCTYPE html>
<html>
<body>
<h1>My first PHP page</h1>
<?php
echo 'Hello World!';
?>
</body>
</html>Note: All PHP statements end with a semicolon (;).
PHP Case Sensitivity
PHP keywords (e.g. if, else, echo, etc.), classes, functions, and user-defined functions are not case-sensitive.
In the example below, both echo statements are legal:
Example
ECHO is the same as echo:
<!DOCTYPE html>
<html>
<body>
<?php
ECHO 'Hello World!<br>';
echo 'Hello World!<br>';
?>
</body>
</html>Note: However; all variable names are case-sensitive!
Look at the example below; only the first statement will display the value of the
$color variable! This is because
$color and
$COLOR are treated as two
different variables:
Example
$COLOR is not same as $color:
<!DOCTYPE html>
<html>
<body>
<?php
$color = "red";
echo "My car is $color<br>";
echo "My house is $COLOR";
?>
</body>
</html>
