Basic PHP Syntax <?php // PHP code goes here ?> The default file extension for PHP files is " .php ". A PHP file normally contains HTML tags, and some PHP scripting code. Below, we have an example of a simple PHP file, with a PHP script that uses a built-in PHP function " echo " to output the text "Hello World!"

PHP has three types of comment syntax: /* */ which serves as block comments, and // as well as # which are used for inline comments. Many examples use the print function instead of the echo function.

The basic structure of a PHP command includes a function, an action, and a semicolon to signify the end of a command.

The “<? php” and “?>” tags tell the PHP engine that everything between them is PHP code. Everything outside the two tags is treated as HTML and ignored by the PHP engine and sent to your browser the same as any other HTML. The important thing to recognize here is that PHP scripts are embedded inside regular HTML pages.