json decode to array

Question

I want to decode a JSON string into an array but I am getting this error.

Fatal error: Cannot use object of type stdClass as array in C:\wamp\www\temp\asklaila.php on line 6

Here is the code:

<?php
$json_string = 'http://www.domain.com/jsondata.json';

$jsondata = file_get_contents($json_string);
$obj = json_decode($jsondata);
print_r($obj['Result']);
?>

Can someone help me fix this?