The generic class ArrayStack uses an array to implement a stack. The private method expandCapacity is used to create a new array of twice the capacity of the old one and copy the content of the old into the new array. It uses the Arrays.copyOf method to do its work.

Rewrite the expandCapacity method without using Arrays.copyOf or any other method. Create a new array of twice the capacity and write a for loop to copy the content of the old array into the new one.