How to return an NSMutableArray from an NSSet

Question

I'm able to put the contents of an NSSet into an NSMutableArray like this:

NSMutableArray *array = [set allObjects]; 

The compiler complains though because [set allObjects] returns an NSArray not an NSMutableArray. How should this be fixed?

Answer 1

Since -allObjects returns an array, you can create a mutable version with:

NSMutableArray *array = [NSMutableArray arrayWithArray:[set allObjects]]; 

Or, alternatively, if you want to handle the object ownership:

NSMutableArray *array = [[set allObjects] mutableCopy];