MATLAB Programming

Example — Assets and Asset Subclasses
switch nargin
case 0
% if no input arguments, create a default object
s.numShares = 0;
s.sharePrice = 0;
a = asset('none',0);
s = class(s,'stock',a);
case 1
% if single argument of class stock, return it
if (isa(varargin{1},'stock'))
s = varargin{1};
else
error('Input argument is not a stock object')
end
case 3
% create object using specified values
s.numShares = varargin{2};
s.sharePrice = varargin{3};
a = asset(varargin{1},'stock',varargin{2} * varargin{3});
s = class(s,'stock',a);
otherwise
error('Wrong number of input arguments')
end
Constructor Calling Syntax
The stock constructor method can be called in one of three ways:
• No input argument — If called with no arguments, the constructor returns
a default object with empty fields.
• Inputargumentisastockobject—Ifcalledwithasingleinputargument
that is a stock object, the constructor returns the input argument. A single
argument that is not a stock object generates an error.
• Three input arguments — If there are three input arguments, the
constructor uses them to define the stock object.
Otherwise, if none of the above three conditions are met, return an error.
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