Can a property of an object become other object's property, but still 'belongs to its owne-CodePudding

I don't know how to express 'property belongs to its owner' properly.

For example, I define classes 'student' and 'teacher'

classdef student < handle

    properties
        name
        homework
    end

    methods
         function obj = student(name)
            obj.name = name;
            obj.homework= struct;
            obj.homework.content='';
            obj.homework.mark=[];
         end
    end
end

classdef teacher < handle
    properties
        collection_homework
    end
end

A=student('A')
A.homework.content='A solution to a math problem'
B=teacher

My question is, according to my design intention, homework is a property of a student, or ‘A is the owner of his homework’. A 'sends' his homework to B, a teacher , so the homework becomes a property of B, but B is not 'the owner' of A's homework. What can teachers do is just to mark the homework and return the homework to students.

But when I try to "send A's homework to B", and B marks A's homework

B.collection_homework=A.homework % put A's homework into B's collection_homework
B.collection_homework.mark=100

I check A, but his homework still is all about content, not mark

A.homework
ans = 
content: 'A solution to a math problem'

That means homework in B's collection_homework doesn't belong to A.

Unless I put 'the whole student' into teacher's collection_homework

B.collection_homework=A % put A into B's collection_homework
B.collection_homework.homework.mark=100

This time I can get B to mark A's homework. Check it

A.homework.marks
ans =
   100

But this is against with my design intention, because A seems to become B's subproperty. For example, B can change A's name by

B.collection_homework.name = 'C'

So what the code should be like to implement 'A send homework to B, and B mark it and send back to A'?

CodePudding user response：

The key point is to define 'homework' as another class

classdef homework < handle
       
    properties
        content
        mark
    end
end

And change definition of 'student'

classdef student < handle & matlab.mixin.Heterogeneous

    properties
        name
        homework
    end

    methods
        function obj = student(name)
            obj.name = name;
            obj.homework = homework();
        end
    end
end

change definition of 'teacher'

classdef teacher < handle
    
    
    properties
        collection_homework
    end
    
    methods
        function obj = teacher()
            obj.collection_homework=homework.empty(0,1);
        end
    end
end

Now test it!

    A=student('A');
    A.homework.content='A solution to a math problem';
    B=teacher;
    B.collection_homework=A.homework;
    B.collection_homework.mark=85;
    
>>B.collection_homework
    
    ans = 
    
      homework - Properties:
    
        content: 'A solution to a math problem'
           mark: 85

>> A.homework

ans = 

  homework - Properties:

    content: 'A solution to a math problem'
       mark: 85

It seems that student and teacher have the same homework. Teacher grades it, and student recieve it.