Key-Value Coding Aggregates on collection

PMOKVOAggregateOnSet.m

        NSArray *numbers = @[@6,@4,@7,@90];
        NSNumber *maxNumber = [numbers valueForKeyPath:@"@max.self"];
        NSNumber *minNumber = [numbers valueForKeyPath:@"@min.self"];
        NSNumber *sumOfNumbers = [numbers valueForKeyPath:@"@sum.self"];
        NSNumber *avgOfNumbers = [numbers valueForKeyPath:@"@avg.self"];
        
        NSLog(@"\nmin: %@\nmax: %@\nsum: %@\navg: %@", minNumber, maxNumber, sumOfNumbers, avgOfNumbers);
        
        NSDate *today = [NSDate date];
        NSArray *dates = @[today,
                               [today dateByAddingTimeInterval: -86400.0],
                               [today dateByAddingTimeInterval: 86400.0]
                               ];

        NSDate *maxDate = [dates valueForKeyPath:@"@max.self"];
        NSDate *minDate = [dates valueForKeyPath:@"@min.self"];
        
        NSLog(@"\nminDate: %@\nmaxDate: %@\n", maxDate, minDate);