The PHP script is executed on the server, and the plain HTML result is sent back to the browser.
Basic PHP Syntax
A PHP script always starts with <?php and ends with ?>. A PHP script can be placed anywhere in the document.
On servers with shorthand-support, you can start a PHP script with <? and end with ?>.
For maximum compatibility, we recommend that you use the standard form (<?php) rather than the shorthand form.
A PHP file must have a .php extension.
A PHP file normally contains HTML tags, and some PHP scripting code.
Below, we have an example of a simple PHP script that sends the text “Hello World” back to the browser:
echo “Hello World”;
Each code line in PHP must end with a semicolon. The semicolon is a separator and is used to distinguish one set of instructions from another.
There are two basic statements to output text with PHP: echo and print.
In the example above we have used the echo statement to output the text “Hello World”.
Comments in PHP
In PHP, we use // to make a one-line comment or /* and */ to make a comment block:
//This is a comment