You can have an array:-You can pass the array as an argument to a method. You can get the method to return an array. You can pass a number and get a method to produce an array that size. You can get the length attribute of any array, which is a common-or-garden int number, and pass it as an argument. You name it, you can do it.
You use  when you are creating the array, or referring to a aprticular member.
If you are referring to a whole array, you miss out the .