Comments

Learn to write single-line (//, #) and multi-line (/* */) comments in PHP.

Comments are used to add explanations to PHP code. PHP ignores comments when running; they do not affect the output.

There are three types: // for single line, # for single line (shell style), and /* */ for multi-line comments.

Example: // this is a note or /* this is also a note */.

Comments make code readable; they are especially useful for explaining complex logic.

Multi-line comments

In PHP, /* */ marks a multi-line comment. This type is ideal for explanations that span several lines.

Example: /* This comment spans two lines */

Multi-line comments cannot be nested: starting another /* */ inside one causes a PHP error.

You can also use multi-line comments to temporarily disable a piece of code.

Write a PHP block. Add a single-line // comment. Then use echo to print "Welcome back"; add \n at the end of the line.

Show example solution

Write a // comment, then add echo "Welcome back\n";.
Example solution:
<?php
// greeting message
echo "Welcome back\n";

Complete the comment line

<?php
____
echo "Welcome back";
?>

Show answer

<?php
// greeting message
echo "Welcome back";
?>