Declaring a class variable within a class, and using it

%% main code

for aa = 1:2

Aclass(aa) = A;

end

for aa = 1:2

Aclass(aa).Dosumthing(aa);

end

%% class A define

classdef A < handle

properties

Bclass = B

end

function Dosumthing(obj, inputs)

Bclass.varis = inputs;

end

end

%% class B define

classdef B < handle

properties

varis = 0;

end

end

The value of Aclass(2).Bclass.varis became 2 even before the value of the for statement variable aa reached 2 by setting the breakpoint. Why?

I want the class variables of Class A to be independent.

Answer 1

[Abhishek]

Hi se chss ,

As per my understanding I think that your problem is that the value of Aclass(2).Bclass.varis became 2 even before the value of the for statement variable aa reached 2.

In the code which you shared, the issue is that you assigned the same instance of class B to the BClass property of both Aclass(1) and Aclass(2). Because of this they refer to the same instance of class B, resulting in shared properties.

In order to maintain that class variables of class A are independent, you need to have separate instances of class B for each instance of class A. You can look into the following code to achieve this :

%% main code

for aa = 1:2

Aclass(aa) = A;

end

for aa = 1:2

Aclass(aa).Dosumthing(aa);

end

%% class A define

classdef A < handle

properties

Bclass

end

methods

function obj = A()

obj.Bclass = B(); % Create a new instance of class B for each instance of class A

end

function Dosumthing(obj, inputs)

obj.Bclass.varis = inputs;

end

end

end

%% class B define

classdef B < handle

properties

varis = 0;

end

end

In this updated code the constructor of class A is modified to create a new instance of class B for each instance of class A.

By making the changes as told above, class variable of class A will be independent.

You can refer following documentation page for constructor method :

https://www.mathworks.com/help/matlab/matlab_oop/class-constructor-methods.html#:~:text=Guidelines%20for%20Constructors%201%20The%20constructor%20has%20the,called%20with%20no%20input%20arguments.%20...%20More%20items