PHP scripts can be placed anywhere in the document.
PHP scripts start with <?php and end with ?>:
<?php // here is the PHP code ?>
The default file extension for PHP files is ".php".
PHP files usually contain HTML tags and some PHP script code.
The following example is a simple PHP file containing a PHP script that prints the text "Hello World!" on a web page using the built-in PHP function "echo":
<!DOCTYPE html> <html> <body> <h1>My first PHP page</h1> <?php echo "Hello World!"; ?> </body> </html>
Note: PHP statements end with a semicolon (;). The closing tag of a PHP code block also automatically indicates a semicolon (so there is no need to use a semicolon on the last line of a PHP code block).
Comments in PHP Comments in
PHP code are not read and executed as a program. Its only purpose is for code editors to read.
Comments are used to:
Make others understand what you're doing - Comments let other programmers understand what you're doing at each step (if you work on a team)
Remind yourself what you've done - Most programmers experience Rework the project after a year or two and then have to rethink what they did. Comments record your thoughts as you write code.
PHP supports three kinds of annotations:
Examples
<!DOCTYPE html> <html> <body> <?php // this is a single line comment # This is also a single line comment /* This is a multi-line comment block it spans Multi-line */ ?> </body> </html>