How to Sort Multi-dimensional Array by Value?

// Sample multi-dimensional array
$data = array(
    array('name' => 'John', 'age' => 25, 'score' => 80),
    array('name' => 'Jane', 'age' => 30, 'score' => 90),
    array('name' => 'Bob', 'age' => 20, 'score' => 70),
    array('name' => 'Mary', 'age' => 35, 'score' => 85),
);

// Function to compare two arrays by a given key
function cmp($a, $b)
{
    return $a['score'] - $b['score'];
}

// Sort the array using the comparison function
usort($data, 'cmp');

// Output the sorted array
print_r($data);