xcode: NSArray slice method?

How can I create a NSSet or NSArray X with first 5 element开发者_如何学JAVAs of NSArray or NSSet Y?

NSArray *X = [NSArray arrayWithObjects:@"foo", @"bar", @"test", @"blah", @"yeah", @"lost", nil];    
NSArray *Y = [X subarrayWithRange:NSMakeRange(0,5)];

The resulting array Y will contain the first five elements of the first array X.

NSMutableArray x = [[NSMutableArray alloc] init];

for (int i=0; i<5; i++)
{
[x addObject:[y objectAtIndex:i]];
}

(y is the other NSMutableArray)