uasort Sort an array with a user-defined comparison function and maintain index association &reftitle.description; booluasort arrayarray callablevalue_compare_func This function sorts an array such that array indices maintain their correlation with the array elements they are associated with, using a user-defined comparison function. This is used mainly when sorting associative arrays where the actual element order is significant. If two members compare as equal, their relative order in the sorted array is undefined. &reftitle.parameters; array The input array. value_compare_func See usort and uksort for examples of user-defined comparison functions. &reftitle.returnvalues; &return.success; &reftitle.examples; 4, 'b' => 8, 'c' => -1, 'd' => -9, 'e' => 2, 'f' => 5, 'g' => 3, 'h' => -4); print_r($array); // Sort and print the resulting array uasort($array, 'cmp'); print_r($array); ?> ]]> &example.outputs; 4 [b] => 8 [c] => -1 [d] => -9 [e] => 2 [f] => 5 [g] => 3 [h] => -4 ) Array ( [d] => -9 [h] => -4 [c] => -1 [e] => 2 [g] => 3 [a] => 4 [f] => 5 [b] => 8 ) ]]> &reftitle.seealso; usort &seealso.array.sorting;