Types of Properties
There are two types of properties:
- Stored properties — Use memory and are part of the object
- Dependent properties — No allocated memory and the get access method calculates
the value when queried
Features of Stored Properties
- Can assign an initial value in the class definition
- Property value is stored when you save the object to a MAT-file
- Can use a set access method to control possible values, but you are not required to use
such methods.
When to Use Stored Properties
- You want to be able to save the property value in a MAT-file
- The property value is not dependent on other property values
Features of Dependent Properties
Dependent properties save memory because property values that depend on other values
are calculated only when needed.
When to Use Dependent Properties
Define properties as dependent when you want to:
- Compute the value of a property from other values (for example, you can compute
area from Width and Height properties). - Provide a value in different formats depending on other values. For example, the size
of a push button in values determined by the current setting of its Units property. - Provide a standard interface where a particular property is or is not used, depending
on other values. For example, different computer platforms can have different
components on a toolbar).
For examples of classes that use dependent properties, see “Calculate Data on Demand”
on page 3-23 and “A Class Hierarchy for Heterogeneous Arrays” on page 20-2.
Ways to Use Properties