MATLAB Object-Oriented Programming

Representative Class Code

In this section...

“Class Calculates Area” on page 5-28

“Description of Class Definition” on page 5-31

Class Calculates Area

The CircleArea class shows the syntax of a typical class definition. This class stores a

value for the radius of a circle and calculates the area of the circle when you request this

information. CircleArea also implements methods to graph, display, and create objects

of the class.

To use the CircleArea class, copy this code into a file named CircleArea.m and save

this file in a folder that is on the MATLAB path.

classdef CircleArea

properties

Radius

end

properties (Constant)

P = pi

end

properties (Dependent)

Area

end

methods

function obj = CircleArea(r)

if nargin > 0

obj.Radius = r;

end

end

function val = get.Area(obj)

val = obj.P*obj.Radius^2;

end

function obj = set.Radius(obj,val)

if val < 0

error('Radius must be positive')

end

obj.Radius = val;

end

5 Class Definition—Syntax Reference