Lab 1 -- Grade Counter
Thursday, April 4, 2002
- Practice using a machine running the UNIX operating system
- Practice with the switch statement
Given a data file of letter grades (A, B, C, D, F), write a program
that will count the number of grades there are of each type.
Getting the data file from a machine running UNIX
In this course, you'll interact with a machine running a different
operating system (OS) than Windows. The UNIX OS is not a
"click-and-drag" interface the way Windows is, but it can still
do everything Windows can (store files, run C++ programs, etc.)
Files are stored hierarchically in UNIX using directories
in the same way that Windows uses folders (and subfolders) to store
files. For example, in UNIX, the file "sample.txt" might be stored
in the directory /public/classes/myfiles. This means that there is
a directory (think folder) called public containing a directory
classes containing a directory called myfiles. And in
the myfiles directory is the "sample.txt" file.
All external files that you'll need for labs will be stored on a machine
called blackduck running the UNIX OS. You can transfer the files
to your local PC using the "SSH Secure File Transfer" application.
You can launch it from your desktop. Once its running, do the
- Under the File menu, click Connect...
- In the dialogue box that appears, type in blackduck.union.edu
for the host. Then type in your username (same as your user name in your
union email address).
- Type in your password. It will be "esc014" and then your username
(with no spaces in between).
- Click OK.
You should now be logged into blackduck. The right-hand window
shows all of the directories and files in your account on blackduck.
All you have to do now is get to the
correct directory and transfer the files. Do the following:
Notice how the file transfer application let you transfer files between
machines using a "click-and-drag" method, even though the UNIX OS itself
does not have such an interface. Later in the course, we'll use the
UNIX OS directly so you can see and use this very different interface
- You should see a directory named "esc014pub". Go into this
directory by double-clicking on it.
- Inside the "esc014pub" directory is another directory called "lab1".
This is the directory you need for your lab. Download this from
blackduck by dragging the entire lab1 folder to your desktop -- put it
in the DesktopAnnex folder where all temporary files should go.
- You've just transferred the file! You can
make sure it worked by going to the
DesktopAnnex folder on your desktop, opening it, and looking for a
folder named "lab1". That's the directory you just transferred!
Inside should be a text file named "examdata.txt". That's the data file
you need for this lab.
- Once you are sure that the transfer worked, you can exit the
file transfer application.
Count the Grades
Now that you have the data file on your PC, it's time to get to the
part of this lab. The file is a list of letter grades: A, B, C, D, or
one grade on each line. You may want to open the data file just to see
the input looks like. There are three important things to note about
- There are no + or - grades. Just whole letter grades.
- Grades may be listed using capital or lower-case letters.
- There may be invalid entries in the file (something not A, B, C, D,
You are to write a program that uses a switch statement to count
total number of each grade and display the totals to the user. The
total number of As should include both capital and lower-case As. The
other grades should be treated similarly. The
total number of invalid entries should also be displayed. Be sure to
name your program with your FULL NAME along with the lab number.
example, I might name my program chrisfernandes_lab1.cpp
How to turn in this lab
In all labs, you will be graded on the correctness of your
neatness, presentation, and style of your program code, and good use of
the C++ language.
It's important to comment your code where appropriate and to do little
things like space things properly, use readable indentation, and also to
make sure the overall design and logic of the program are coherent.
You should turn in a hard copy of your source code with the output
appended at the bottom as a comment.
For practice, you'll also turn this lab in electronically on
BlackBoard. Go to
http://online.union.edu and drop your source code (just the .cpp file)
into the dropbox
as demonstrated by your instructor. Be sure the file is named
with your FULL NAME and lab number!
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