MATLAB Object-Oriented Programming

Static Data

In this section...

“What Is Static Data” on page 4-2

“Static Variable” on page 4-2

“Static Data Object” on page 4-3

“Constant Data” on page 4-5

What Is Static Data

Static data refers to data that all objects of the class share and that you can modify after

creation.

Use static data to define counters used by class instances or other data that is shared

among all objects of a class. Unlike instance data, static data does not vary from one

object to another. MATLAB provides several ways to define static data, depending on your

requirements.

Static Variable

Classes can use a persistent variable to store static data. Define a static method or local

function in which you create a persistent variable. The method or function provides

access to this variable. Use this technique when you want to store one or two variables.

Saving an object of the class defining the persistent variable does not save the static data

associated with the class. To save your static data in an object, or define more extensive

data, use the static data object technique “Static Data Object” on page 4-3

Implementation

The StoreData class defines a static method that declares a persistent variable Var. The

setgetVar method provides set and get access to the data in the persistent variable.

Because the setgetVar method has public access, you can set and get the data stored in

the persistent variable globally. Control the scope of access by setting the method Access

attribute.

classdef StoreData

methods (Static)

4 Static Data