most effecient way to order an array by sub elements?

Question

I have a multidimensional array.

$array[0] = array(1, 8, 2);    
$array[1] = array(5, 6, 15);
$array[2] = array(-8, 2, 1025);

I am wondering what the most efficient way to order the parent array by a particular property of it's sub array. For example, I want to put them in ascending order of $sub_array[1], so the parent array would be ordered 2,1,0.

Answer 1

Use http://www.php.net/manual/en/function.usort.php and write a callback function that implements the sort condition you want.