 Again, what if you wanted to use the comparable interface? Again, we were just showing it as strings. If you take a look here, just like anything, you would say your class, you would say what that class extends and what that class implements. In this case, student is comparable to another student. I can take two students and say which one is better, basically. Now, okay, compare the GPA or whatever, who's got the higher whatever. Well, in this case, all I'm saying is whose ID is larger than the other ones. And again, I have to implement this because it's being inherited from comparable. And so I have to decide sort of how I get the negative 101. In this case, I say, well, if my student, if this guy, this is get ID is larger than this guy's ID. So if we're talking about this, this dot ID, we'll say, for example, equals zero, well, we'll say it equals 10. And this guy's ID, s dot ID equals 15. Does this ID, is this ID greater than 15? No, so I skip it, false. Is it less than? In our case, yes, 10 is less than 15, so I would return a negative one.