[Tutor] OOP design - Law of Demeter

[Harry Kattz]

Greetings All,

> For examnple you need to assign students to groups and 
> move students from one group to another. You probably 
> want to list the students in a group. Applying the 
> principle that objects should "do it to themselves" 
> (sometimes known as the law of demeter(sp?)) then 
> students probably need a method to setGroup() and/or 
> moveGroup(group). The group objects need a listStudents() 
> method too.

Here's the Law of Demeter:

Do not refer to class C in method m unless C is the type of 
1). an instance variable; 
2). an argument of m; 
3). an object created in m; 
4). a global variable.



Good luck,
Sam