Matlab class property specification

classdef MAtWarning
    properties
        P@uint8=uint8(1); % undocumented way
        % P(1,1)uint8=uint8(1); % R2021b style
    end
    methods(Static=true)
        function Test
            clear;clc;
            Instance=MAtWarning;
            aa=Instance.P;
            fprintf(2,'%u...\n',aa(1));
        end
    end
end

I'm migrating a project from R2016a to R2021b. Many classes use the undocumented way to specify properties.

The undocumented way gets warning in R2021b, and the R2021b style is obviously better, but I need time to see if all the code works fine at R2021b, so I hope there is a way for the code to work fine both in R2016a & R2021b, so that I could switch the MCR whenever I want.

Suppress the warning does not seems like a perfect solution to me.

warning('off','MATLAB:class:PropUsingAtSyntax');

Hope someone can help me.

Answer 1

[Yair Altman]

Starting in 16a, you can use the new syntax as long as you don't specify the dimensions. In other words, the following 2 propery definitions are essentially equivalent:

classdef test
   properties
       prop1@uint8 = uint8(1); % undocumented way
       prop2 uint8 = uint8(1); % documented way
   end
end

Note that the documented dimentionality specification (e.g. (1,1) instead of scalar) requires a more recent release - it will not run on 16a. But as long as you don't specify dimentionality and as long as you are sure that the code will not be ran in 15b or earlier, then it should be perfectly safe to simply remove the @ symbol in all your class property definitions, and this code will work on any relase since 16a.

Additional information and comparison between the documented/undocumented mechanisms: https://undocumentedmatlab.com/articles/setting-class-property-types-2

[XGQ]

It works!

Thank you so much! Not only for this answer, but also for all the things learned from your amazing website all these years, helped me a lot!