Problem With Sorting array

If you assign key/value pairs to an array, the comma is used to separate the pairs. The keynames must be strings. If you need numeric values with decimals, use a dot, not a comma.

E.g.:
$myArray = array(
'10'=>12.7,
'4'=>7
);

Will result in :
$myArray[10] => 12.7
$myArray[4] => 7