MATLAB Object-Oriented Programming

Properties Containing Objects

In this section...

“Assigning Objects as Default Property Values” on page 8-66

“Assigning to Read-Only Properties Containing Objects” on page 8-66

“Assignment Behavior” on page 8-66

Assigning Objects as Default Property Values

MATLAB evaluates property default values only once when loading the class. MATLAB

does not reevaluate the assignment each time you create an object of that class. If you

assign an object as a default property value in the class definition, MATLAB calls the

constructor for that object only once when loading the class.

NoteEvaluation of property default values occurs only when the value is first needed,

and only once when MATLAB first initializes the class. MATLAB does not reevaluate the

expression each time you create an instance of the class.

For more information on the evaluation of expressions that you assign as property default

values, see “When MATLAB Evaluates Expressions” on page 6-13.

Assigning to Read-Only Properties Containing Objects

When a class defines a property with private or protected SetAccess, and that property

contains an object which itself has properties, assignment behavior depends on whether

the property contains a handle or a value object:

• Handle object – you can set properties on handle objects contained in read-only
  properties


• Value object – you cannot set properties on value object contained in read-only
  properties.

Assignment Behavior

These classes illustrate the assignment behavior:

8 Properties — Storing Class Data