array_intersect_uassoc Computes the intersection of arrays with additional index check, compares indexes by a callback function arrayarray_intersect_uassoc arrayarray1 arrayarray2 array ... callbackkey_compare_func array_intersect_uassoc returns an array containing all the values of array1 that are present in all the arguments. Note that the keys are used in the comparison unlike in array_intersect. The index comparison is done by a user supplied callback function. It must return an integer less than, equal to, or greater than zero if the first argument is considered to be respectively less than, equal to, or greater than the second. "green", "b" => "brown", "c" => "blue", "red"); $array2 = array("a" => "GREEN", "B" => "brown", "yellow", "red"); print_r(array_intersect_uassoc($array1, $array2, "strcasecmp")); ?> ]]> &example.outputs; brown ) ]]> See also array_intersect, array_intersect_assoc, array_uintersect_assoc, array_uintersect_uassoc, array_intersect_key and array_intersect_ukey.