When copying one resource to another, you're actually creating a reference to the original resource, this is not an actual copy.
This is illustrated by the following example:
echo '<pre>'; // create an image resource $image = imagecreate(100, 100); // print the resource var_dump($image); // the above prints "resource(30) of type (gd)" // create a copy // (actually creating a reference, // although =& is not implicitly used) $copy = $image; // print the reference var_dump($copy); // the above prints "resource(30) of type (gd)", same as before // destroy the image resource imagedestroy($image); // this prints "resource(30) of type (Unknown)" // so the image was destroyed var_dump($image); // this also prints "resource(30) of type (Unknown)" // meaning that the reference points to a destroyed image var_dump($copy); echo '</pre>';
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