array_uintersect_uassoc Computes the intersection of arrays with additional index check. Both the data and the indexes are compared by using a callback functions. arrayarray_uintersect_uassoc arrayarray1 arrayarray2 array ... callbackdata_compare_func callbackkey_compare_func array_uintersect_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_uintersect. Both the data and the indexes are compared by using a callback functions. "green", "b" => "brown", "c" => "blue", "red"); $array2 = array("a" => "GREEN", "B" => "brown", "yellow", "red"); print_r(array_uintersect_uassoc($array1, $array2, "strcasecmp", "strcasecmp")); ?> ]]> Result will look like: green [b] => brown ) ]]> For comparison is used the 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. See also array_uintersect, array_intersect_assoc, array_intersect_uassoc and array_uintersect_assoc.