create a class and a function which will return an optional variable in matlab

main.m
classdef MyClass
    methods
        function out = myFunction(obj, in)
            if in > 0
                out = sqrt(in);
            else
                out = [];
            end
        end
    end
end
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12 lines

main.m
% create an instance of the MyClass class
obj = MyClass();

% call the myFunction method with an input of 16
result1 = obj.myFunction(16); % result1 = 4

% call the myFunction method with an input of -1
result2 = obj.myFunction(-1); % result2 = []
248 chars
9 lines