MATLAB Object-Oriented Programming

Mutable and Immutable Properties

In this section...

“Set Access to Property Values” on page 8-22

“Define Immutable Property” on page 8-22

Set Access to Property Values

The property SetAccess attribute enables you to determine under what conditions code

can modify object property values. There are four levels of set access that provide varying

degrees of access to object property values:

• SetAccess = public — Any code with access to an object can set public property
  values. There are differences between the behavior of handle and value classes with
  respect to modifying object properties.


• SetAccess = protected — Only code executing from within class methods or
  methods of subclasses can set property values. You cannot change the value of an
  object property unless the class or any of its subclasses defines a method to do so.


• SetAccess = private — Only the defining class can set property values. You can
  change the value of an object property only if the class defines a method that sets the
  property.


• SetAccess = immutable — Property value is set during construction. You cannot
  change the value of an immutable property after the object is created. Set the value of
  the property as a default or in the class constructor.

Define Immutable Property

In this class definition, only the Immute class constructor can set the value of the

CurrentDate property:

classdef Immute

properties (SetAccess = immutable)

CurrentDate

end

methods

function obj = Immute

obj.CurrentDate = date;

end

8 Properties — Storing Class Data