Grouping of Custom Objects in Objective-C

Question

I have and array of custom objects of Person Class

Person : NSObject{
    NSString *firstName;
    NSString *lastName; 
    NSString *age;
}

NSMutableArray          


        

Answer 1

A Drop in code to help you doing it,

    -(NSMutableArray *)sortArray:(NSArray *)arrayTosort withKey:(NSString *)key ascending:(BOOL)_ascending
{
    NSSortDescriptor *sortDescriptor;
    sortDescriptor = [[NSSortDescriptor alloc] initWithKey:key
                                                 ascending:_ascending] ;
    NSArray *sortDescriptors = [NSArray arrayWithObject:sortDescriptor];

    return [[arrayTosort sortedArrayUsingDescriptors:sortDescriptors] mutableCopy];
}

here key is key or keypath.