However, if you dont know the size of the array before and you would like to have something which has dynamic size and you can choose to use a List<> collection.
For List, you can continue like follows:
List<string> arguements = new List<string>();
arguements.add("C:\\Users\\All Users\\Apple\\Some File.msi");
arguements.add("C:\\Users\\All Users\\Apple\\Another FIle.msi");
and then to access the values you can just use it like u do it in the case of arrays i.e.
to access the first element you can use arguements and similarly arguements for accessing the second element.
Arraylist is exactly similar as List in terms of usage.
P.S. You will need to import the System.Collections.Generic namespace to use the Lists in your code.