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PHP Tutorial

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PHP Comments


Comments in PHP

A comment in PHP code is a line that is not executed as a part of the program. Its only purpose is to be read by someone who is looking at the code.

Comments can be used to:

  • Let others understand your code
  • Remind yourself of what you did - Most programmers have experienced coming back to their own work a year or two later and having to re-figure out what they did. Comments can remind you of what you were thinking when you wrote the code
  • Leave out some parts of your code

PHP supports several ways of commenting:

Example

Syntax for comments in PHP code:

// This is a single-line comment

# This is also a single-line comment

/* This is a
multi-line comment */
Try it Yourself »

Single Line Comments

Single line comments start with //.

Any text between // and the end of the line will be ignored (will not be executed).

You can also use # for single line comments, but in this tutorial we will use //.

The following examples uses a single-line comment as an explanation:

Example

A comment before the code:

// Outputs a welcome message:
echo "Welcome Home!";
Try it Yourself »

Example

A comment at the end of a line:

echo "Welcome Home!"; // Outputs a welcome message
Try it Yourself »

Comments to Ignore Code

We can use comments to prevent code lines from being executed:

Example

Do not display a welcome message:

// echo "Welcome Home!";
Try it Yourself »

PHP Exercises

Test Yourself With Exercises

Exercise:

Insert the PHP comment syntax to make sure the following code line is not executed:

 print("Hello World");

Start the Exercise


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