How to sort a mutablensarray?

I made this code to sort an nsmutablearray but how to send back an NSMutablearray ? i need this because a add information later in my mutablearray.

-(NSArray*)trierTableau:(NSMutableArray*)ptableau champsFiltre:(NSString*) champs{

NSSortDescriptor *lastDescriptor =
[[[NSSo开发者_如何学编程rtDescriptor alloc]
  initWithKey:champs
  ascending:YES
  selector:@selector(localizedCaseInsensitiveCompare:)] autorelease];

NSArray * descriptors = [NSArray arrayWithObjects:lastDescriptor, nil];
NSArray * sortedArray = [ptableau sortedArrayUsingDescriptors:descriptors];

return sortedArray;

}

If you want to sort your NSMutableArray in-place, then you could call sortUsingDescriptors: instead of sortedArrayUsingDescriptors:, which returns a sorted copy of your array. sortUsingDescriptors: will sort the existing NSMutableArray.

e.g.

-(void)trierTableau:(NSMutableArray*)ptableau champsFiltre:(NSString*) champs {
    NSSortDescriptor *lastDescriptor =
    [[[NSSortDescriptor alloc]
      initWithKey:champs
      ascending:YES
      selector:@selector(localizedCaseInsensitiveCompare:)] autorelease];

    NSArray * descriptors = [NSArray arrayWithObjects:lastDescriptor, nil];
    [ptableau sortUsingDescriptors:descriptors];
}

This way you don't have to return the NSMutableArray either.

If you actually want a sorted copy of the array, then you'll need to create a new NSMutableArray, use addObjectsFromArray: to copy the elements over, and then use sortUsingDescriptors: on the new array. But I think that sorting the existing NSMutableArray is probably what you'll want.