Homework 2: Draw virtual function tables (VFTs)

Homework 2
After unzipping the HW2.zip, you’ll notice a subdirectory userid, and under that a directory HW2Code
with some C++ code. This code will be used in each of the three steps below. A Makefile is provided in
the C directory where the Part C solution will go.
Part A.
Draw virtual function tables (VFTs) for Base and Derived, and arrows from the VFTs to the code
executed. You can do this by hand if desired. These should be in a .pdf or JPEG file with the appropriate
extension with the name of A.
Part B.
Examine the code in HW2Code. In the file HW2.cpp you will notice that each line has an Sx, where x is
an integer, after it. You will need to put what is printed out by these lines for Part B.
You could compile and run the program but you won’t learn anything, and C++ is incapable of learning,
so there really isn’t any value in that other than a few points and perhaps discovering on the test that
you really don’t know what is going on. Feel free to run it after putting what you think the output is
into B.txt, to check your results. If you go some wrong, figure out why and correct your results.
Fill in your answers in B.txt using an editor, by leaving a space after the “:” an putting your answer.
Thus, in B.txt, for S0 you would have the line
S0: XYZ
If multiple lines are printed by a statement, answer like this (this isn’t the correct answer, by the way):
19: Derived::bar
Base::f4
If a line gives a compile time error, answer “Err” (without the quote marks). For the rest of the program
assume that the error line was not executed.
If a line prints nothing, and does not give an error, answer “Ok” (also without the quote marks).
Part C.
By only changing the Derived class, make the call to f4() in S15 and S25 of main print “Derived::f4”.
Again, by only changing the Derived class, make the call in S19 and S29 print out
Derived::foo1
Derived::f1
How to turn in your homework:
Use the same directory structure as exists under the HW2 directory. That is, you should have a userid
directory. Inside that directory there should be a file A.pdf (or A.jpg or A.jpeg) file with the answer to A
and a file B.txt with the answer to B. Also in the userid directory there will be a C directory that contains
the code for Part C. Zip up and turn in userid.zip.