You will get more answers from here:
https://bitcointalk.org/index.php?board=4.0Supposing you get this result:
Array ( [proof-of-work] => 6.2216203 [proof-of-stake] => 3.62663766 [search-interval] => 1 )
When you make:
print_r($bitcoin->getdifficulty());
To display them separately:
<?php
$difficulty = $bitcoin->getdifficulty();
// Show PoW
echo $difficulty["proof-of-work"];
// Show PoS
echo $difficulty["proof-of-stake"];
?>
Learn basics of Arrays from here:
http://php.net/manual/en/language.types.array.php