Property access in subclass

Hello everyone, i am new to the OOP in Matlab.

I have a superclass A

classdef A
    properties
        Property1
    end
    
    methods
        function obj = A()
             obj.Property1 = {};
        end
        
        function add(obj,inputArg)
            obj.Property1{length(obj.Property1) + 1}=inputArg;
        end
        
        function str=output(obj)
            str="";
            for i=1:length(obj.Property1)
                str=strcat(str," - ",string(obj.Property1{i}),newline);
            end
        end
    end
end

and a subclass B

classdef B < A
    methods
        function obj = B()
            obj.add('Start');
        end
        
        function outputArg = format(obj)
            outputArg = strcat("List:",newline,obj.output());
        end
    end
end

Now I run the following test code:

x=B();
x.add('End');
fprintf(x.format());

The result is

List:

although I expected

List:
 - Start
 - End

. What have I done wrong?

Thanks a lot

Stephan

Answer 1

[Steven Lord]

As you've defined A and B they are value classes but you're using them like they are handle classes. See this documentation page and the "Object Modification" section on this other documentation page for more information.

[Stephan]

Thanks a lot!

classdef A < handle

Solve my problem!