Array sorting by key value in php

I would like to sort below array based on amount but I don't know how. Anyone help me

Array(
    [0] => Array
     (
          [id] => 1

          [amount] => 20
     )
     [1] => Array
     (
          [id] => 2
          [amount] => 30
     )
     [2] => Array
     (
          [id] => 3

          [amount] => 10
     )
)

Answer

Use usort.

E.g

function sortByAmount($x, $y) {

    return $x['amount'] - $y['amount'];
}

usort($array, 'sortByAmount');
echo "
"; print_r($array);