1. Choose File-->New-->Project
2. In the Project Type window, click on Visual C++. (You might have to first open the "Other Languages" option.)
3. In the Template window, click on CLR Empty Project. (Later we will create more compilicated kinds of projects.)
4. In the Name textbox, type the name: heatwave
5. Please write down the path that's listed in the Location box. You'll need to know this location later when you save the files that you've created.
6. Click the OK button.

1. In the Solution Explorer window, RIGHT click on Source Files, choose Add, click on New Item.
2. In the Templates window, click on C++ File (.cpp)
3. In the Name text box, type the name heatwave.cxx --this will be the name of your first C++ program. Most programmers use ".cpp" for the file type of a C++ program, but we like to be a bit different, so please use .cxx instead!
4. Click the Add button.

//****************************************************************************
// ABOUT THIS PROGRAM (heatwave.cxx)
//   Written by: Michael Main, January 4, 2007
//   Email address: main@colorado.edu
//   Exercise for student: Irving Forbush
//
// INPUT: The program prompts the user to enter the height and radius of
//   a tree. To make things simpler, we assume that the tree is a perfect
//   cylinder.  The height is entered first (measured in feet), and then the
//   radius is entered (also measured in feet).
//   The program then prompts the user to enter the number of cubic feet of
//   wood required to heat a house for one day.
//
// OUTPUT: The program calculates the number of days that the tree will heat
//   a house, and outputs this value.
//
// EXAMPLE DIALOG:
//   How tall is your tree in feet?
//   13.2
//   What is the radius of the tree in feet?
//   2.1
//   How many cubic feet of wood will heat a house for a day?
//   40.2
//   That tree will heat a house for 4.54921 days.
//**************************************************************************

#include <iostream>           // Provides cin, cout
#include <cstdlib>            // Provides EXIT_SUCCESS
using namespace std;

const double PI = 3.14159;    // Defined to make the program readable

int main () 
{
    double height;            // Height of a tree in feet
    double radius;            // Radius of a tree in feet
    double requirement;       // Cubic feet of wood to heat house for a day
    double volume;            // Volume of the tree in cubic feet
    double days;              // Number of days that tree will heat house

    // Prompt user for input and read responses
    cout << "How tall is your tree in feet?" << endl;
    cin >> height;
    cout << "What is the radius of the tree in feet?" << endl;
    cin >> radius;
    cout << "How many cubic feet of wood will heat a house for a day?" << endl;
    cin >> requirement;

    // Computations
    volume = height * PI * radius * radius;
    days = volume / requirement;

    // Output days
    cout << "That tree will heat a house for " << days << " days." << endl;

    return EXIT_SUCCESS;
}

After you have copied this program, please compile the project (Build-->BuildSolution) and proceed to the next step.

Setting a Breakpoint and Starting the Debugger

Today you'll start by running a debugger session using the heatwave program. To get the debugger started on the heatwave program:

1. In the gray bar to the left of your code, click on the first line with a cout instruction. A red dot appears in the gray bar to indicate that you have set a "breakpoint," which is a point in your code where the debugger will stop to let you examine things.

   The program will pause every time it reaches this line of code. If you later want to remove the breakpoint, you can do so by clicking again on the red dot.

2. Click the Debug menu and select Start Debugging.

Stepping Through the Program One Line at a Time (the F10 instruction)

When the debugger starts, the bottom of the screen opens a window called the "Call Stack." We'll examine the purpose of this window later. For now, notice that there is a yellow arrow in the gray bar to the left of your code. This arrow marks the line of code that has not yet been executed, but it is just about to be executed. For our example, this is the first cout statement of the main function.

In order to execute that one line, press the F10 key. Notice that the message has now appeared in the console output window, yay! Also, the yellow arrow moved down one line, so the program is about to execute the cin statement (but it hasn't yet done so).

Watching a Variable

Suppose that you want to know the value that is currently stored in some variable. You can get this value by clicking in the code window and holding the mouse over the name of the variable in the code. Do this now with the height variable and you will most likely see a meaningless number. That is because we haven't yet put any value in the height variable. So, let's put a value in that variable and check it's value again:

1. Press F10 to execute the cin statement.
2. Type a number in the console window. I typed 42.8 and then pressed return.
3. Check to see what value is now stored in the height variable (mine has 42.799999999999 (the reason for the difference is that not all real numbers can be exactly represented in the base 2 format that the computer uses).

If you want to permanently watch the value of a variable, you can do so by clicking the Debug menu, choosing QuickWatch, typing the name of the variable, and then clicking the Add Watch button. Permanent watches are displayed in another small window below your code.

Go ahead and put a permanent watch on the volume variable, then step through the program one line at a time until you notice that the volume variable has changed because of an assignment statement. Notice that when the value of the volume variable changed, its value in the watch window is displayed in red.

Running to the Next Breakpoint

For this step, please set another breakpoint at the bottom of your main function (on the return EXIT_SUCCESS line).

If you want to run the program all the way to the next breakpoint, you may do so by pressing the F5 key. Try this now.

Note: When you are running the program with debugging, it is a good idea to alway set a breakpoint on the last line of the main program. Otherwise the program will end and the console window will close before you can see the output.