正在修改重复数组中的PHP对象

Question

I have a multidimensional array, and some of the elements are objects. I want to end up with 2 arrays, one which has had all string values and object properties passed through my esc() function, and one which is the unmodified original.

Given the following code:

$raw = $data;
echo $raw['obj']->description; // Prints '< >Test Desc'

array_walk_recursive($data, function (&$item, $key){
   if(is_string($item)) {
      $item = esc($item);
   } elseif(is_object($item)) {
      foreach ($item as $property => $value)  {
          if(is_string($value)) {
              $item->$property = esc($value);
          }
      }
   }
});

echo $data['obj']->description; // Prints '&lt; &gt;Test Desc' - Correct
echo $raw['obj']->description; // Prints '&lt; &gt;Test Desc' - Incorrect

I would expect $raw to be entirely unmodified, and $data to have been processed through esc(). This is the case except for object properties. For some reason the object in $raw is also modified, so that the two echo lines print different values, why is this?

Answer 1

since PHP 5 objects are always pass-by-reference.

you have to "clone" the objects to really copy them.

see http://php.net/manual/en/language.oop5.references.php for details.