public class Greeter {
  // instance fields
  private String myName;
  
  // constructors
  public Greeter() {
    myName = "World";
  }
  
  public Greeter(String name) {
    myName = name;
  }

  // methods
  public String sayHello(){
    // String message = "Hello World!";
    String message = "Hello " + myName + "!";
    return message;
  }

  public String sayGoodbye(){
    // String message = "Goodby World!";
    String message = "Goodbye " + myName + "!";
    return message;
  }

}