MATLAB: Calling a function inside an app

Question

Hi,

I am trying to understand how to call a function inside an app. So, I've created a simple app to get the sum of two numbers (a,b), and c is their sum. There's a pushbutton in the app whose function is to run this created functon outside the app and assign the outcome to the variable "c". However when I run the app, I get this error:

Unable to resolve the name app.a.

Error in su (line 2)

c = app.a + app.b;

This is the app code

properties (Access = public)
        a % Description

        b % Description
        end
    % Callbacks that handle component events
    methods (Access = private)
        % Value changed function: aEditField
        function aEditFieldValueChanged(app, event)
            app.a = app.aEditField.Value;
        end
        % Value changed function: bEditField
        function bEditFieldValueChanged(app, event)
            app.b = app.bEditField.Value;            
        end
        % Button pushed function: Button
        function ButtonPushed(app, event)
            su;
            app.cEditField.Value = c;

And this is the "su" function

function su
c = app.a + app.b;
end

Any help on why I get this error would be really appreciated.

Thanks

Answer 1

Functions need inputs and outputs, so you will need to define the function su as

function out = su(app)
    out = app.a+app.b
end

and inside your app

function ButtonPushed(app, event)
    c = su(app);
    app.cEditField.Value = c;
end

Now, as to whether this structure for the app and function is a good structure, that's a separate question.