Java-Test

class StackX
   {
   private final int SIZE = 20;
   private int[] st;
   private int top;

   public StackX()           // constructor
      {
      st = new int[SIZE];    // make array
      top = -1;
      }

   public void push(int j)   // put item on stack
      { st[++top] = j; }

   public int pop()          // take item off stack
      { return st[top--]; }

   public int peek()         // peek at top of stack
      { return st[top]; }

   public boolean isEmpty()  // true if nothing on stack
      { return (top == -1); }

   }