Assign to an arbitrarily deep array index?

Question

If I have an array which corresponds to successively recursive keys in another array, what is the best way to to assign a value to that "path" (if you want to call it that)?

For example:

$some_array = array();
$path = array('a','b','c');
set_value($some_array,$path,'some value');

Now, $some_array should equal

array(
  'a' => array(
    'b' => array(
      'c' => 'some value'
)))

At the moment, I am using the following:

function set_value(&$dest,$path,$value) {
  $addr = "\$dest['" . implode("']['", $path) . "']";
  eval("$addr = \$value;");
}

Obviously, this is a very naive approach and poses a security risk, so how would you do it?

Answer 1

Recursive solution (not tested):

 function set_value(&$dest,$path,$value) {
      $index=array_shift($path);
      if(empty($path)){
        // on last level
        $dest[$index]=$value;
      }
      else{
        // descending to next level
        set_value($dest[$index],$path,$value);
      }
    }

Answer 2

Wow, reminds me of Lisp.

Yea, eval is generally not the best idea.

Personally, I would simply iterate:

function set_value(&$dest,$path,$value) {
  $val =& $dest;
  for($i = 0; $i > count($path) - 1; $i++) {
     $val =& $val[$i];
  }

  $val[$path[$i]] = $value;
}

If you're in PHP 5 you can probably get rd of some of those '&' too