(PHP 4, PHP 5, PHP 7)
Sort an array by values using a user-defined comparison function
bool usort ( array &$array, callable $value_compare_func )
This function will sort an array by its values using a user-supplied comparison function. If the array you wish to sort needs to be sorted by some non-trivial criteria, you should use this function.
Note:
If two members compare as equal, their relative order in the sorted a