If you want to sorting multidimensional array using php then check this code , hope it will help you.

 <?php
$yourarray = array(
    0 => array(
        'bill_number' => 3,
        'amount' => 100
    ),
    1 => array(
        'bill_number' => 4,
        'amount' => 50
    ),
    2 => array(
        'bill_number' => 5,
        'amount' => 150
    ),
);
 
function sortByOrder($a, $b)
{
    return $a['amount'] - $b['amount'];
}
 
usort($yourarray, 'sortByOrder');
echo "<pre>";
print_r($yourarray);
?>

this code will give this output :

Array
(
    [0] => Array
        (
            [bill_number] => 4
            [amount] => 50
        )
 
    [1] => Array
        (
            [bill_number] => 3
            [amount] => 100
        )
 
    [2] => Array
        (
            [bill_number] => 5
            [amount] => 150
        )
 
)