The activities listed here presume you have access to the GNU g++ compiler with the Code::Blocks IDE. You will find these installed in the CS Dept. PCs. You can also find instructions on installing these free programs on the CS 333 Library page.

Open a browser and go to the CS Dept home page. Look for the link to the “Virtual Computing Lab”. Follow the instructions given there under “Connecting” to open a Remote Desktop Connection to a virtual lab machine.

Log in with your account info as per the earlier Account Setup lab.

• If the login window comes up with something like “vclab_yourLoginName_”, click on “Switch User” and then “Other User” so that you can log in as “csnet_yourLoginName_”.

  You should now be looking at a window with an image of a complete Windows Vista desktop. This is a “Virtual PC” with all of the software that the CS Dept normally provides on its physical PCs in its own labs. However, this virtual machine is designed for the kind of remote access that you are now enjoying.

• One thing you might consider doing almost immediately is clicking on the taskbar “start” button and selecting “Windows Security”. One of the options given is to change your password. If you are running a newly created account with the initial default password, you want to change this immediately because it’s quite easy for others to guess your default.

A few general cautions about working with virtual PCs.

• Don’t try to store anything on the C: drive or on the desktop of this machine. The drives on these virtual machines are reset periodically. Either way, you won’t be able to recover that lost file.

  • Your “My Documents” area is safe, however, because it gets saved to a network store when you log out and reloaded when you log back in. However, if you have a lot of material stored there, it significantly slows down your login and logout.

  • You should have a Z: drive on the machine that actually maps to your account space on the Unix network. That’s a safe place to keep your work.

  • When you used Remote Desktop Connection to connect to this virtual machine, there was probably an “Options” button. Under the “Local Resources” tab, you have the option of mapping the disk drives of your local PC (the one you are sitting at) onto the virtual machine. This makes for a very convenient (if somewhat slow) way to share files between the two.

• When you are done working, be sure to actually log out from the virtual PC. Don’t simply disconnect. That ties up a virtual machine (for at least a while) and slows down the virtual machine server for everyone else.

Now if you are on campus and are in one of the CS Dept labs, you can, if you wish, log out of the virtual PC and complete the remainder of the assignment working directly on that PC instead of via a virtual machine. But even then, keep in mind that the virtual PCs are available to you from anywhere with an Internet connection.

Luckily, there are several good-quality, free IDEs as well. In this course we will use Code::Blocks. The course Library page includes instructions on getting this, together with the g++ compiler, if you want to install it on your own PC. However, you will find it already in place on the CS Dept virtual PCs.

Run Code::Blocks (you should find this in the Start button menu on the CS lab PCs).[^ If you have installed it yourself, then the first time you run it, it may try to locate compilers it can work with. If so, select “GNU GCC Compiler”. Click “Set as default”, then “OK”. It should find your new installation of g++.)]

Let’s start out with a very simple project. Select “File->New->Project.” Select “Console Application” and click “Go”. Move through the Wizard, choosing C++ as the language. Give the project the title “FirstProject”, click on the “…” button to choose a place in which to save your work.

• Keep the earlier discussion about safe places to store your work in mind as you choose this.

Accept the rest of the defaults until the wizard closes.

On the left you can now see your project structure. If you open the Sources folder, you can see that it has already created a basic main.cpp file for you. Double-click this to open it in the editor.

Let’s make some changes before compiling this. Change the program to look like this:

#include <iostream> 
#include <string> 

using namespace std; 

int main() 
{ 
  string greeting = "Hello world!"; 
  cout << 
  return 0; 
}

Save this and click the Build button (the blue gear) to attempt compilation. You should see some compilation errors due to the incomplete statement.[^ If you see an error message that says you are using “an invalid compiler”, then Code::Blocks did not actually locate the compiler properly. From the “Settings” menu, select “Compiler and Debugger”, On the tab “Toolchain excutables”, Use the “…” button for the “Compiler’s Installation Directory” to point it to the directory where you installed MinGW. ]

Now put the cursor at the end of the “cout” line and type “greet” (without the quotes). Pause a moment and notice that a box pops up suggesting a possible completion for this variable name. Hit Tab to accept this suggestion. Now finish the program like this:

#include <iostream> 
#include <string> 

using namespace std; 

int main() 
{
  string greeting = "Hello world!"; 
  cout << greeting << endl;
  return 0; 
}

Save and again click the Build button. This time things should succeed.

Click the Run button (the blue triangle) to execute your program.

When you are satisfied, close that project.

#include <string>
#include <iostream>

using namespace std;

// Farenheit to Centigrade converter
int main()
{
  double f, c;
  cout << "Enter a temperature measured in degrees Farenheit: "
       << flush;
  cin >> f; // reads f from the keyboard
  c = (5.0 / 9.0) * (f - 32.0);
  cout << "In Centigrade, that would be " << c << " degrees."
       << endl;
  return 0;
}

#include <string>
#include <iostream>

using namespace std;

// Farenheit to Centigrade converter
int main()
{
  cout << "Enter a temperature measured in degrees Farenheit: "
       << flush;
  double f;
  cin >> f; // reads f from the keyboard
  double c = (5.0 / 9.0) * (f - 32.0);
  cout << "In Centigrade, that would be " << c << " degrees."
       << endl;
  return 0;
}

to minimize the time during which either variable is left uninitialized.

Try making those changes, run the debugger again, and single-step through. Do you see any difference in how the variables behave?