MATLAB Programming

Example — Assets and Asset Subclasses
TheStocksetMethod
The set method provides a “property name” interface like the get method.
It is designed to update the number of shares, the share value, and the
descriptor. The current value and the date are automatically updated.
function s = set(s,varargin)
% SET Set stock properties to the specified values
% and return the updated object
propertyArgIn = varargin;
while length(propertyArgIn) >= 2,
prop = propertyArgIn{1};
val = propertyArgIn{2};
propertyArgIn = propertyArgIn(3:end);
switch prop
case 'NumberShares'
s.numShares = val;
case 'SharePrice'
s.sharePrice = val;
case 'Descriptor'
s.asset = set(s.asset,'Descriptor',val);
otherwise
error('Invalid property')
end
end
s.asset = set(s.asset,'CurrentValue',...
s.numShares * s.sharePrice,'Date',date);
Note that this function creates and returns a new stock object with the new
values, which you then copy over the old value. For example, given the stock
object,
s = stock('XYZ',100,25);
the following set command updates the share price.
s = set(s,'SharePrice',36);
It is necessary to copy over the original stock object (i.e., assign the output to
s) because MATLAB does not support passing arguments by reference. Hence
the set method actually operates on a copy of the object.
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