If the size of the stack is zero, true is returned; otherwise, false is returned : Stack « Collections « Java Tutorial

1. Java Tutorial
2. Collections
3. Stack

import java.util.Stack;

public class MainClass {
  public static void main (String args[]) {
    Stack s = new Stack();
    s.push("A");
    s.push("B");
    s.push("C");

    System.out.println(s.pop());
    System.out.println(s.empty());
  }
}

C
false