Operator overload

My favourite syntax trick is to overload operators. One can indeed redefine - pretty easily by the way - the behavior of the almost every operators, event the most basic ones like +, . or =. The limitation is that you can overload operators for your own objects, not Matlab's built-in objects like numbers or strings.

A basic example

Let's define a basket class to store fruits and vegetables:

classdef basket < handle
   
    % --- Properties ----------------------------
    properties
        
        fruits = {};
        vegetables = {};
        
    end
    
    % --- Methods -------------------------------
    methods
        
        % The clas constructor (empty)
        function this = basket(), end
        
    end
    
end

And let's define two baskets:

% Define the first basket
A = basket;
A.fruits = {'apple', 'banana', 'orange'};
A.vegetables = {'avocado', 'broccoli', 'carrot'};

% Define the second basket
Z = basket;
Z.fruits = {'watermelon'};
Z.vegetables = {'yam', 'zucchini'};

So far, so good. Now let's modify the basket class to add a method plus:

classdef basket < handle
   
    % --- Properties ----------------------------
    properties
        
        fruits = {};
        vegetables = {};
        
    end
    
    % --- Methods -------------------------------
    methods
        
        % The clas constructor (empty)
        function this = basket(), end
        
        % Overload the + operator
        function B = plus(this, other)
        
           B = basket();
           B.fruits = [this.fruits other.fruits];
           B.vegetables = [this.vegetables other.vegetables];
            
        end
        
    end
    
end

This method overloads the + operator, and we can now concatenate the contents of the baskets with +:

>> Final = A+Z

Final = 

  basket with properties:

        fruits: {'apple'  'banana'  'orange'  'watermelon'}
    vegetables: {'avocado'  'broccoli'  'carrot'  'yam'  'zucchini'}

Going further

The complete list of overloadable operators and the associated method names are available in the documentation. Interestingly, the subsref method handles indexing, more precisely the A(i), A{i} and A.i syntaxes. The subsasgn and subsindex methods can also be really interesting in some cases, so you definitively should check their documentation.

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