NSIndexPath getIndexes method....how?

Question

Am confused with the use of this method and the documentation that lists it as a (void) method.

"on return the index path's indexes"

where does it return anything too?

Should it not be:

- (NSIndexPath *)getIndexes:(NSUInteger *)indexes

getIndexes: Provides a reference to the index path’s indexes.

- (void)getIndexes:(NSUInteger *)indexes

Parameters indexes Pointer to an unsigned integer array. On return, the index path’s indexes. Availability Available in iOS 2.0 and later. Declared In NSIndexPath.h

Answer 1

You have to allocate the NSUInteger array of size [indexPath length] and pass it as argument. The return value will be written there. You have to release that array yourself or do nothing it was created on stack like this:

NSUInteger array[[indexPath length]];
[indexPath getIndexes: array];

Answer 2

Maybe the next sentence explains the reason

It is the developer’s responsibility to allocate the memory for the C array.

It's actually a pointer to a C array that will be filled for you with the indexes, so there's no reason to additionally return it from the function - you already know its address.

You can use the function as follows

NSUInteger indexCount = [indices count];
NSUInteger buffer[indexCount];
[indices getIndexes:buffer maxCount:indexCount inIndexRange:nil];