MATLAB Programming

9 Classes and Objects
Classes and Objects: An Overview
• “Features of Object-Oriented Programming” on page 9-3
• “MATLAB Data Class Hierarchy” on page 9-3
• “Creating Objects” on page 9-4
• “Invoking Methods on Objects” on page 9-4
• “Private Methods” on page 9-5
• “Helper Functions” on page 9-6
• “Debugging Class Methods” on page 9-6
• “Setting Up Class Directories” on page 9-6
• “Data Structure” on page 9-7
• “Tips for C++ and Java Programmers” on page 9-8
Youcanviewclassesasnewdatatypeshavingspecificbehaviorsdefined
fortheclass. Forexample,apolynomial class might redefine the addition
operator (+) so that it correctly performs the operation of addition on
polynomials. Operations defined to work with objects of a particular class
are known as methods of that class.
You can also view classes as new items that you can treat as single entities.
An example is an arrow object that MATLAB can display on graphs (perhaps
composed of MATLAB line and patch objects) and that has properties like a
Handle Graphics object. You can create an arrow simply by instantiating
the arrow class.
You can add classes to your MATLAB environment by specifying a MATLAB
structure that provides data storage for the object and creating a class
directory containing M-files that operate on the object. These M-files contain
the methods for the class. The class directory can also include functions that
define the way various MATLAB operators, including arithmetic operations,
subscript referencing, and concatenation, apply to the objects. Redefining how
abuilt-inoperatorworksforyourclassisknownasoverloading the operator.
9-2