MATLAB Object-Oriented Programming

Handle-Compatible Classes and Heterogeneous Arrays

In this section...

“Heterogeneous Arrays” on page 12-48

“Methods Must Be Sealed” on page 12-48

“Template Technique” on page 12-48

Heterogeneous Arrays

A heterogeneous array contains objects of different classes. Members of a heterogeneous

array have a common superclass, but can belong to different subclasses. See the

matlab.mixin.Heterogeneous class for more information on heterogeneous arrays.

The matlab.mixin.Heterogeneous class is a handle-compatible class.

Methods Must Be Sealed

You can invoke only those methods that are sealed by the common superclass on

heterogeneous arrays (Sealed attribute set to true). Sealed methods prevent subclasses

from overriding those methods and guarantee that methods called on heterogeneous

arrays have the same definition for the entire array.

Subclasses cannot override sealed methods. In situations requiring subclasses to

specialize methods defined by a utility class, you can employ the design pattern referred

to as the template method.

Template Technique

Suppose that you implement a handle compatible class that works with heterogeneous

arrays. This approach enables you to seal public methods, while providing a way for each

subclass to specialize how the method works on each subclass instance. In the handle

compatible class:

• Define a sealed method that accepts a heterogeneous array as input.


• Define a protected, abstract method that each subclass must implement.


• Within the sealed method, call the overridden method for each array element.

12 How to Build on Other Classes