Can someone tell me why i am getting this error

Question

helo, I am trying to write 3 seperate classes and use inheritence between them, a small brek down is class Thought is suppose to have a method messege that prints out "I'm a teacher" and slass Advice is suppose to be a subclass of Thought and suppose to have the same method ut to print out "I'm your student" and class Message is suppose to have a main method that instantiates the two other classes and makes them work. I have written the code, this should have been simple, but these are the errors i am getting when compiling Messeges:
Messages.java [14:1] variable thought might not have been initialized
output =thought.Message() + "\n" +advice.Message();
^
Messages.java [14:1] variable advice might not have been initialized
output =thought.Message() + "\n" +advice.Message();
Here is the code"
public class Thought{
protected String message="";
public String Message()
    message="I'm a teacher.";
    return message;
}//end class
public class Advice extends Thought{
private String message="";
public String Message()
message="I'm your student.";
    return message;
}//end class
import javax.swing.JOptionPane;
public class Messages
    public static void main(String args[])
Thought thought;
Advice advice;
String output="";
output =thought.Message() + "\n" +advice.Message();
JOptionPane.showMessageDialog(null,output,"Inheritence",
JOptionPane.INFORMATION_MESSAGE);
System.exit(0);
}//end main
}//end classAny help would be appreciated.

Answer 1

Hi,
I had gone through the code you have posted and I agree with atmguy that the errors that were thrown were due to the fact that you have not initialized the objects from the main method. You have to use the new keyword to inityialize the objects that you are creating.
Secondly you have stated that you have used inheritance and created three classes. But I find that the inheritance has not been practised at all. Try removing the "extends Thought" portion and then also your code would work just fine. It is as good as creating two seprate classes and using them from a third containing the main function. Hope this clears all your querries.
cheers
Aviroop