How to call delegate methods from other class in Swift?

How do I create an array of abstract class objects in MATLAB?

• As an example, suppose I have created an abstract class called Shape and two subclasses called Circle and Rectangle that both implement an (abstract) method called Draw. I would like to be able to create a number of Circle and Rectangle objects, store them in an array and call Draw on each array object by iterating through the array. I have tried something like the following: Shape.m: classdef (Abstract) Shape < handle methods (Abstract) Draw(obj); end end Circle.m: classdef Circle < Shape methods function obj = Draw(obj) disp('This is a circle'); end end end Rectangle.m: classdef Rectangle < Shape methods function obj = Draw(obj) disp('This is a rectangle'); end end end test.m: shapes = Shape.empty(); myrect = Rectangle(); mycirc = Circle(); shapes(end + 1) = myrect; shapes(end + 1) = mycirc; for i = 1:size(shapes,1) shapes(i).Draw(); end When I try to run test.m, I get the following error message: Error using Shape.empty Abstract classes cannot be instantiated. Class 'Shape' defines abstract methods and/or properties. Error in test (line 1) shapes = Shape.empty();

• Answer:

  You can use a cell array. A cell array's contents can be any type of data structure my_c_array{1}=rect_object my_c_array{3}=shape_object my_c_array{4}=47.23 my_c_array{5}='monkey' then later you can grab your structs from the array and do whatever you want with them tmp_var=my_c_array{1}