create array of objects of a class in another class MATLAB - matlab

Question

I am trying to create an array of objects of a class Cell in another class Systemin MATLAB. The classCell` is:
classdef Cell
properties
ID;
EntityID;
ZoneID;
NeighborID;
State;
nextChangeTime;
end
methods
% Define the constructor
function obj = Cell()
obj.ID = zeros(1);
obj.EntityID = zeros(1);
obj.ZoneID = zeros(1);
obj.NeighborID = zeros(1);
obj.State = zeros(1);
obj.nextChangeTime = zeros(1);
end
end
Now I have another class System. I try to make an array of Cell objects like this:
classdef System
properties
Cells;
end
methods
function obj = System(dimx,dimy)
obj.Cells(dimx,dimy) = Cell();
end
end
But I think I am using the wrong format. Not sure if this is possible. Any suggestions on how to accomplish this would be appreciated.

Answer 1

In order to be able to create arrays of objects of user-defined class (e.g. Cell class), it is convenient to have the default constructor for the user-defined class. The default constructor is the one that takes no arguments (i.e. when nargin==0). When creating arrays, the implicit initialization of the array's objects is done by this constructor. If this constructor is missing, trying to build arrays by "extending" a scalar object will generate an error.
Another way of creating arrays of objects (without defining a default constructor) is by using horzcat, vertcat and cat.
Aaaaand... when accessing the properties of an object, don't forget to mention the object you're accessing:
obj.Cells = Cell.empty(0,0); % Force the type of empty Cells to Cell class
obj.Cells(dimx,dimy) = Cell();