PHP print_r function within heredoc string?

Question

I've tried a few different ways and per Is it possible to use php functions inside heredoc? it seems like the first one (for the GET) should work?

But it doesn't. Any way to do this simply, or should I just manually include the debug section?

  function bottom_module() {
    $print_r = print_r;

    $html = <<<"OUTPUT"
      <footer>
        ...
      </footer>

      <aside id="debug">
        <hr>
        <h3>Debug Area</h3>
        <pre>
          GET Contains:
          {$print_r($_GET)}
          POST Contains:
          $print_r($_POST)
          SESSION Contains:
          print_r($_SESSION)
        </pre>
      </aside>

    </body>
  </html>
  OUTPUT;
    echo $html;
  }

Unrelated to the problem you're currently having, but $print_r = print_r; refers to a constant called print_r. What you almost certainly intended to write was $print_r = 'print_r'; - that is, set $print_r to be a string with the content 'print_r'. In old versions of PHP, an odd feature guessed that undefined constants were intended to be strings, but it always issued a Notice or Warning while doing so, and the feature was removed in PHP 8.0 so it is an error instead. — IMSoP
– IMSoP, Commented Aug 13, 2022 at 15:46

iSteeb · Accepted Answer · 2022-08-14 06:26:58Z

4

What you will probably find is that the print_r() is displaying the value rather than including it in the output.

You should try using the second parameter which if set to true will return the value as a string instead...

   <pre>
      GET Contains:
      {$print_r($_GET, true)}

EDIT from OP for clarity: this solves the issue but as another reply said, $print_r must be declared as $print_r = 'print_r';

edited Aug 14, 2022 at 6:26

iSteeb

597 bronze badges

answered Aug 13, 2022 at 15:38

Nigel Ren

57.2k11 gold badges49 silver badges59 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

PHP print_r function within heredoc string?

1 Answer 1

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related