PHP comments are used to give a brief description about any specific line of code or about a module in the code to make the code more user-friendly.

PHP Comments can be of two types:

Single line comments can be used in two manners, either like C++ style single line comment (using // before the comment line) or Unix Shell style single line comment (using # before the comment line).

Multi line comments can be used for commenting a part of the code or to write a multiple lines description about the code. The lines enclosed between /* */ are considered as multi line comments.

Example 1: Representing Single Line Comments

<!DOCTYPE html> <html> <body>   <?php $txt1 = "Sum of 1234 and 4321 is:";$txt2 = “Difference of 1234 and 4321 is:";   $x = 1234;$y = 4321;   // Sum of two numbers echo "<h3>" . $txt1 . "</h3>"; echo$x + $y; # Difference of two numbers echo "<h3>" .$txt2 . "</h3>"; echo $x -$y;   ?>   </body> </html>

Example 2: Representing Multi Line Comments
Program of Sum and Difference of two variables in PHP

<!DOCTYPE html> <html> <body>   <?php $txt1 = "Sum of 1234 and 4321 is:";$txt2 = “Difference of 1234 and 4321 is:"; $x = 1234;$y = 4321;   echo "<h3>" . $txt1 . "</h3>"; echo$x + $y; echo "<h3>" .$txt2 . "</h3>"; echo $x -$y;   ?>   </body> </html>