MATLAB Object-Oriented Programming

newValue = c.Amount - amount;

if newValue < 0

c.Amount = 0;

disp('Your balance is $0.00')

else

c.Amount = newValue;

end

end

end

end

Default Object

The design of this class hierarchy uses an abstract root class (Assets). Therefore, the

Assets class must specify a concrete class to use as a default object by overriding

getDefaultScalarElement. In this case, options include:

• Use one of the existing concrete classes for the default object.


• Define a concrete class in the hierarchy to use for the default object.

This implementation adds the DefaultAsset class to the hierarchy as a subclass of the

Assets class. MATLAB creates objects of this class when:

• Creating arrays using indexed assignment with gaps in index numbers


• Loading heterogeneous arrays from MAT-files when MATLAB cannot find the class of
  an array element.

This diagram shows the addition of the DefaultAsset class:

20 Designing Related Classes