для массива
NSMutableArray *arr1 = [NSMutableArray arrayWithObjects:@"1", @"2", @"a", @"b", nil];
for (NSString *obj in arr1) {
// do stuff
}
А для карты
NSMutableArray *keys = [NSMutableArray arrayWithObjects:@"1", @"2", @"3", @"4", nil];
NSMutableArray *values = [NSMutableArray arrayWithObjects:@"a", @"b", @"c", @"d", nil];
NSDictionary *dict = [NSDictionary dictionaryWithObjects:keys forKeys:values];
for (id key in dict) {
id value = [dict valueForKey:key];
// do stuff with value
}