Stack.java

public class Stack extends ArrayStore {
   public void addAll(Object[] a) {
      int newLength = length + a.length;
      growTo(length + a.length);
      for (int i = 0; i < a.length; i++) {
         array[length+i] = a[i];
      };
      length = newLength;
   }
   public String toString () {
      StringBuffer ws = new StringBuffer();
      ws.append("top->");
      for (int i = length-1; i >= 0; i--) {
         ws.append(array[i]+" ");
      };
      return ws.toString();
   }
}