Equivalent Methods of Python __setitem__ and _getitem__ methods

What are the equivalent methods in matlab of the python methods __setitem__ and _getitem__?

Thank you,

Virginio

[Stephen23]

Read the "Description" very carefully:

https://www.mathworks.com/help/matlab/ref/subsref.html

https://www.mathworks.com/help/matlab/ref/subsasgn.html

Answer 1

[Jaimin]

Hi @Virginio,

In MATLAB, you can replicate the functionality of Python's “__getitem__” and “__setitem__” methods by overloading the “subsref” and “subsasgn” methods within a class. These methods enable you to define custom behavior for indexing operations.

Kindly refer to the code snippet below for an example.

classdef MyClass
    properties(Access=public)
        Data
    end
    
    methods
        function obj = MyClass(data)
            % Constructor to initialize the Data property
            obj.Data = data;
        end
        
        function value = subsref(obj, S)
            % Override subsref to define custom indexing behavior
            switch S(1).type
                case '()'
                    % Handle parentheses indexing
                    value = obj.Data(S.subs{:});
                otherwise
                    error('Not a valid indexing expression');
            end
        end
        
        function obj = subsasgn(obj, S, value)
            % Override subsasgn to define custom assignment behavior
            switch S(1).type
                case '()'
                    % Handle parentheses indexing
                    obj.Data(S.subs{:}) = value;
                otherwise
                    error('Not a valid indexing expression');
            end
        end
    end
end

For more information on “subsref” and “subsasgn” methods kindly refer following MathWorks Documentation.

subsref: https://www.mathworks.com/help/matlab/ref/subsref.html

subsasgn: https://www.mathworks.com/help/matlab/ref/subsasgn.html

I hope this will be helpful.

[Bob Randall]

Nice! Very concise and clear example, Thank you, Jaimin.