You can use recursive function like below:

function object_to_array($obj, &$arr)
{
 if (!is_object($obj) && !is_array($obj))
 {
  $arr = $obj;
  return $arr;
 }

 foreach (key => $value)
 {
  if (!empty($value))
  {
   key] = array();
   objToArray($value, key]);
  }
  else {key] = $value;}
 }

 return $arr;
}

The best way would be to manage your data structure as an object from the start if you have the ability:

$a = (object) array( ... ); $a->prop = $value; //and so on

But the quickest way would be the approach supplied by @CharlieS, using json_decode(json_encode($a)).

You could also run the array through a recursive function to accomplish the same. I have not benchmarked this against the json approach but:

function convert_array_to_obj_recursive($a) {
    if (is_array($a) ) {
        foreach(k => $v) {
            if (is_integer($k)) {
                // only need this if you want to keep the array indexes separate
                // from the object notation: eg. a['index'][$k] = convert_array_to_obj_recursive($v);
            }
            else {
                k] = convert_array_to_obj_recursive($v);
            }
        }

        return (object) $a;
    }

    // else maintain the type of $a
    return $a; 
}

Hope that helps.

EDIT: json_encode + json_decode will create an object as desired. But, if the array was numerical or mixed indexes (eg. array('a', 'b', 'foo'=>'bar') ), you will not be able to reference the numerical indexes with object notation (eg. o[1]). the above function places all the numerical indexes into the 'index' property, which is itself a numerical array. so, you would then be able to do $o->index[1]. This keeps the distinction of a converted array from a created object and leaves the option to merge objects that may have numerical properties.

First of all, we can't see the scope. All your code is private (object properties and the method). Show the scope and we can help you better.

The problem seems to be here:

   if (!empty($value))
   {
       $arr[$key] = array();
       objToArray($value, $arr[$key]);
   }

You are passing a second argument that doesn't defined in the method

 private function objToArray($obj){...}

So you are passing a value to objToArray(), that value is a string I guess, and when it reach this line:

   $arr = array();

if(!is_object($obj) && !is_array($obj)){
     $arr = $obj;
     die("invalid data");
}

Then it will display "invalid data", and empty your array.

Please check this if this okay

$obj = new stdClass($array); or
$obj = json_decode(json_encode($array));

<?php
    $arr = array(array(141,151,161,140),2,3,array(101,202,array(303,404),407));
    function array_oned($arrays){
        static $temp_array = array();
        foreach($arrays as $key){
            if(is_array($key)){
                array_oned($key);
            }else {
                $temp_array [] = $key;
            }
        }
        return $temp_array;
    }
    echo print_r(array_oned($arr));

?>

Did you mean something like this ?