MATLAB: Constructor for a class, that accepts name-value pairs for setting properties

classconstructorMATLABoopproperties

Hello! Could anyone advise on how to write a class constructor, that accepts name-value pairs for setting properties? For the untouched properties it must use predefined values. Using like this:

X = classX('Prop1',val1,'Prop3',val3)

Thanks

Best Answer

With a recent Matlab version, you can do,

classdef classX
    properties
     Prop1, Prop3;   
    end
    
    methods
        function obj=classX(namedArgs)
    
            arguments
             namedArgs.Prop1=default1;
             namedArgs.Prop3=default3;
            end
            
            obj.Prop1=namedArgs.Prop1;
            obj.Prop3=namedArgs.Prop3;
        end
    end
    
end

Related Solutions

MATLAB: How to override inherited methods

You can't do what you asked. If you could, you could relax the property setting validation to the point where your subClass instance wouldn't be a valid superClass instance.

You may be able to do what you want, however. Your superClass's property setter could call a normal instance method that subClass could overload. See the trustedSubclassSetterHelper methods in the attached superClass495080 and subClass495080. That helper doesn't actually set the property (otherwise you get into a loop) but merely provides the updated value. This means that the value would have to be something both superClass495080 (in set.prop1) and subClass495080 (in trustedSubclassSetterHelper) accept as a valid value.

>> Q = superClass495080
Q = 
  superClass495080 with properties:
    prop1: 'Hello!'
    prop2: 'My name is'
>> Q2 = subClass495080
Q2 = 
  subClass495080 with properties:
    prop3: 'Dom.'
    prop1: 'Hello World!'
    prop2: 'My name is'

MATLAB: Name-value pairs

You can use reshape

function C = name_value_pairs(varargin)
    if nargin == 0 || rem(numel(varargin),2) ~= 0
        C = {};
        return;
    end
    
    C = reshape(varargin, 2, []).';
    if ~all(cellfun(@ischar, C))
        C = {}
    end
end

Best Answer

Related Solutions

MATLAB: How to override inherited methods

MATLAB: Name-value pairs

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