MATLAB Programming

Building on Other Classes
baseclass. Youcannotaccessthebaseclass object’s fields directly from the
derived class; you must use access methods defined for the base class.
Derived Class Constructor
The constructor function for a derived class has two special characteristics:
• It calls the constructor function for the base class to create the inherited
fields.
• It requires a special calling syntax for the class function, specifying both
the derived class and the base class.
The syntax for establishing simple inheritance using the class function is:
derivedObj = class(derivedObj, 'derivedClass', baseObj);
Simple inheritance can span more than one generation. If a base class is
itself an inherited class, the derived class object automatically inherits from
theoriginalbaseclass.
Visibility of Class Properties and Methods
Thebaseclassdoesnothaveaccesstothe derived class properties. The
derived class cannot access the base class properties directly, but must use
base class access methods (e.g., get or subsref method) to access the base
class properties. From the derived class methods, this access is accomplished
via the base class field in the derived class structure. For example, when a
constructor creates a derived class object c,
c = class(c, 'derivedClassname', baseObject);
MATLAB automatically creates a field, c.baseClassname, intheobject’s
structure that contains the base object. You could then have a statement in
the derived class display method that calls the base class display method.
display(c.baseClassname)
See “Designing the Stock Class” on page 9-49 for examples that use simple
inheritance.
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