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PHP: Comments

Almost every programming language allows you to add comments to your code. This is text that isn't part of the program and is needed for programmers to make notes. They help explain how the code works, what errors need to be corrected, or what not to forget to add later.

Comments in PHP come in two flavors:

Single line comments

_Single line comments start with //. Any text can go after these characters, the whole line will be left alone when the program is run.

A comment can take up a whole line. Or you can create several comments if one line isn't enough:


// For Winterfell!
// For Lanisters!

Or it can go after code on the same line:

print_r('I am the King'); // For Lannisters!

Multi-line comments

Multiline comments start with /* and end with */. Each line between them must begin with a *.

 * The night is dark and
 * full of terrors.
print_r('I am the King');


Create a one-line comment with the text: You know nothing, Jon Snow!.

The exercise doesn't pass checking. What to do? 😶

If you've reached a deadlock it's time to ask your question in the «Discussions». How ask a question correctly:

  • Be sure to attach the test output, without it it's almost impossible to figure out what went wrong, even if you show your code. It's complicated for developers to execute code in their heads, but having a mistake before their eyes most probably will be helpful.
In my environment the code works, but not here 🤨

Tests are designed so that they test the solution in different ways and against different data. Often the solution works with one kind of input data but doesn't work with others. Check the «Tests» tab to figure this out, you can find hints at the error output.

My code is different from the teacher's one 🤔

It's fine. 🙆 One task in programming can be solved in many different ways. If your code passed all tests, it complies with the task conditions.

In some rare cases, the solution may be adjusted to the tests, but this can be seen immediately.

I've read the lessons but nothing is clear 🙄

It's hard to make educational materials that will suit everyone. We do our best but there is always something to improve. If you see a material that is not clear to you, describe the problem in “Discussions”. It will be great if you'll write unclear points in the question form. Usually, we need a few days for corrections.

By the way, you can participate in courses improvement. There is a link below to the lessons course code which you can edit right in your browser.


  • Comment text in program code that doesn't affect functionality, and is added by programmers for themselves and their colleagues.

    // single-line comment

    * multiline comment
    * multiline comment

If you got stuck and don't know what to do, you can ask a question in our community