public class IntegerArrayStack extends IntegerStack { 

    IntegerArrayStack() {
        this(10);
    }

    IntegerArrayStack(int capacity) {
        super(capacity);
    }

    /** Returns the value in the stack at position pos.
        The bottom of the stack has position 0. */
    public int valueAt(int pos) {
        return stack[pos];
    }

    public static void main(String[] args) { 

        IntegerArrayStack is = new IntegerArrayStack();

        // int n = is.pop();  this should cause an exception
        // int n = is.top();  this should cause an exception

        if (is.isEmpty())
            System.out.println("stack is empty");
        else
            System.out.println("stack is not empty");

        for (int i = 0; i < 10; i++)
            is.push(i);

        is.push(10);

        System.out.println("stack before popping: " + is);
        System.out.println(is.pop());
        System.out.println("stack after popping: " + is);
        System.out.println("top of stack is: " + is.top());

        for (int i = 0; i < 10; i++)
            System.out.println(is.valueAt(i) + " ");

    }
}