mb_convert_encoding

<?

$string = ["🐘", "🐘"];
$to_encoding = 'UTF-8';

$return = mb_convert_encoding($string, $to_encoding);

print_r($return);

?>

Array
(
    [0] => 🐘
    [1] => 🐘
)

<?

$string = "🐘";
$to_encoding = 'UTF-8';

$return = mb_convert_encoding($string, $to_encoding);

echo $return;

?>

🐘

<?

$string = "🐘";
$to_encoding = 'UTF-8';
$from_encoding = ['auto', 'ASCII', 'ISO-8859-1'];

$return = mb_convert_encoding($string, $to_encoding, $from_encoding);

echo $return;

?>

🐘

<?

$string = "🐘";
$to_encoding = 'UTF-8';
$from_encoding = 'auto, ASCII, ISO-8859-1';

$return = mb_convert_encoding($string, $to_encoding, $from_encoding);

echo $return;

?>

🐘

<?

$string = "🐘";
$to_encoding = 'UTF-8';
$from_encoding = null;

$return = mb_convert_encoding($string, $to_encoding, $from_encoding);

echo $return;

?>

🐘