Creating a property list programmatically

gistfile1.m

        NSMutableDictionary *rootObj = [NSMutableDictionary dictionaryWithCapacity:2];
        NSDictionary        *innerDict;
        NSString            *name;
        NSDate              *dob;
        NSArray             *scores;
 
        scores = [NSArray arrayWithObjects:[NSNumber numberWithInt:6],
                                           [NSNumber numberWithFloat:4.6], 
                                           [NSNumber numberWithLong:6.0000034], 
                                           nil];
       
        name = @"George Washington";
        dob = [NSDate dateWithString:@"1732-02-17 04:32:00 +0300"];

        innerDict = [NSDictionary dictionaryWithObjects:[NSArray arrayWithObjects: name, dob, scores, nil]
                                                forKeys:[NSArray arrayWithObjects:@"Name", @"DOB", @"Scores"]];

        //Adds the key value to the property list
        [rootObj setObject:innerDict forKey:@"Washington"];
 
        scores = [NSArray arrayWithObjects:[NSNumber numberWithInt:8],
                                           [NSNumber numberWithFloat:4.9],
                                           [NSNumber numberWithLong:9.003433], 
                                           nil];
        name = @"Abraham Lincoln";
        dob = [NSDate dateWithString:@"1809-02-12 13:18:00 +0400"];

        innerDict = [NSDictionary dictionaryWithObjects:[NSArray arrayWithObjects: name, dob, scores, nil]
                                                forKeys:[NSArray arrayWithObjects:@"Name", @"DOB", @"Scores"]];
        
        //Adds the key value to the property list
        [rootObj setObject:innerDict forKey:@"Lincoln"];
 
        id plist = [NSPropertyListSerialization dataFromPropertyList:(id)rootObj
                                                              format:NSPropertyListXMLFormat_v1_0 
                                                    errorDescription:&error];