class Player3 {

	// fields - used to store data for instances of the class
	String userName = null;
	int age = 0;

	// constructors
	Player3(String user) {
		this.userName = user;
	}	

	// overloading constructor
	Player3(String user, int age) {
		this.userName = user;
		if (age >= 0) {
			this.age = age;
		}
	}

	@Override 
	public boolean equals(Object obj) {

		if (!(obj instanceof Player)) {
			return false;
		}

		Player p = (Player) obj;

		if(p.userName.equals(this.userName)) {
			return true;
		}
		return false;
	}	

}