Value of array is not shown and getting no errors

What am I doing wrong here? I have a PHP array which I want to access in WordPress. Here is a sample:

Array
(
    [data] => Array
        (
            [0] => Array
                (
                    [id] => 124
                    [name] => MyName
                    [supertype] => Mso
                    [subtypes] => Array
                        (
                            [0] => Stage 2
                        )

                    [level] => 42

And I am trying to show this like so:

<?php echo ( $myvalue['0']->id); ?>

However, this does not work as it only outputs: " "

I also tried [0], but that did not work.

What am I doing wrong?