declaring array of an object X with unknown size objective c

Question

How would I go about declaring an array in the .h file of an unknown size that I will calculate say in the a function inside the class ?

For example, I might have 20 or

Answer 1

You have two choices.

1) Make it an NSArray of NSArrays, or

2) Declare it as:

NSArray **arrays_of_unknown_size;

Then you can malloc/calloc the pointer when you know the actual size. Then you need to assign an NSArray to each element of the C-array.