Lecture Object oriented programming - Lecture No 24

CSC241: Object Oriented Programming

Lecture No 24

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Previous Lecture
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Efficient string class
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Resolve problem while deleting String objects

Dynamic Type Information
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dynamic_cast operator
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Checking class type
pDerv1 = dynamic_cast<Derv1*>(pUnknown)

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Changing Pointer Types
pDerv1 = dynamic_cast<Derv1*>(pUnknown)

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typeid operator
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Class name of object

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Today’s Lecture
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Example programs
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Publication company

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Distance class

Intro to Generic Programming
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template

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Example program 1
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Imagine the publishing company that markets
both book and audiocassette versions of its
works
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create a class publication (private data: title,
price)

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derive two classes:

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book, which adds a page count (type int)

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tape, which adds a playing time in minutes (type float)

Each of the three classes should have a getdata()
function to get its data from the user at the
keyboard, and a putdata() function to display the

data
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Cont.
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In a loop, ask the user for data about a book or tape,
and use new to create an object of type book or tape

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When the user has finished entering the data display
the resulting data using a for loop and a single
statement such as
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pubarr[j]->putdata();
Write a
program

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Example program 2
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In the Distance class, create an overloaded *
operator so that two distances can be multiplied
together. Make it a friend function so that you

can use such expressions as
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dist1 = 7.5 * dist2;

Write a main() program to test this operator.
Write a
program

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