GameObject[] array VS arraylist for Gameobject?

Hi folks,
I new in Unity 3d and my requirement is to have dynamic array like in Objective “NSMutableArray” so I want to ask which of one I should use either use GameObject or arraylist for GameObject. I just little use to get own knowledge, for arraylist is dynamic but for this I have to type cast every time when I need to fetch element from this like. And GameObject don’t need type cast but it is not static as far as I know. Kindly guide me where I am wrong and suggest me better.
Thanks

Don’t use ArrayList for anything, ever. Use a generic List if you want an array that’s resizable.