1. Starting Visual C++
2. Creating a Workspace
3. Creating a Program
4. Compiling, Linking, and Building your Program
5. Running your Program
6. Saving your Output
7. Dealing with Errors
8. Summary

1. Starting Visual C++

First, start up Visual C++ from the Start->Programs->Microsoft Visual C++ 6.0->Microsoft Visual C++ 6.0 menu.

Was the description of the location of Visual C++ given above correct? If not, record the correct location on your lab sheet..

Step 2:

You should be greeted by an invaluable "Tip of the Day". After reading this tip, you can either choose "Close" or continue fascinating yourself with more tips by clicking "Next Tip". When you tire of reading tips, or perhaps you are ordered to turn out the lights and go to sleep, choose "Close". You are then presented with the Microsoft Developer Studio Visual C++ environment, as shown below:

The steps you will complete in the sections that follow are:

• create a workspace in which to develop and run programs;
• create a program;
• compile the program;
• run the program;
• debug the program.

On your lab sheet, describe any differences in appearance between the picture shown and the Visual C++ application on your desktop.

2. Creating a Workspace

In order to create a workspace, select "New" from the "File" menu. You will be presented with a dialog box displaying a dizzying assortment of project types. The type you should select is "Win32 Console Application", shown highlighted in the figure below.

On your lab sheet, record the names of at least 3 other types of projects you can create.

Step 2:

Click the text box below "Project name:" and type in a name for your project (e.g., "testproject" as shown). Then click "OK".

You may be asked some questions regarding your choice. Make sure you select the "empty project" option when asked. Otherwise, you can ignore the dialogue widows and just hit "return" and watch them go by.

On your lab sheet, record the 3 other types of console applications you can create.

Step 3:

A new window appears in the left of the screen showing the "testproject" workspace you have created.

3. Creating a Program

Now, you are ready to create a program in your workspace. To do this, click the 'page' icon (this appears at the leftmost part of the toolbar beneath the "File" menu). This creates a blank window to the right of the "testproject" workspace. In this window, you will enter your program.

Step 2:

Click in the blank area, then enter the program shown below. This program is syntactically correct as it appears, meaning there are no errors in it such as spelling, capitalization, or improper use of symbols. Type everything exactly as it appears. Pay special attention to symbols such as semicolons (;), curly braces ({ }), slashes (/) and backslashes (\). Use the tab key for indentation.

IMPORTANT: Before typing anything, you might want to turn on the Emacs-compatibility mode. You can do this by going to the Tools->Options menu. Next, choose the Compatibility tab and then from the Current source editor emulation drop-down list, choose Epsilon. Finally, click Yes when it asks if you're sure you want to change the emulation and voila! You're now able to use your Emacs key-bindings!

There are several things you should know about to help with typing the program:

• You can move the cursor up by pressing CTRL-p, down by pressing CTRL-n, left by pressing CTRL-b, or right by pressing CTRL-f.
• When you indent with the tab key, the next line you enter will automatically be indented to align with the previous line. To remove indenting, you only need to backspace once for each tab character that appears on the line.
• You can select an entire word by positioning the cursor inside the word and double-clicking. You can also select an entire line by positioning the cursor beside the line, inside the gray left margin area, and clicking.

  The Program:

  //----------------------------------------------- // Program Name: Sample Program 1 // Purpose: This program converts two // English measurements to // metric. // Coder: Joe B. Hacking // Date: 2003-09-08 // Last Modified: 2003-09-10 by Ricky J. Sethi //----------------------------------------------- #include <iostream> using namespace std; int main(void) { const double INCHES_PER_METER = 39.37; const double POUNDS_PER_KG = 2.24; short height; short weight; cout << "METRIC CONVERTER" << endl << endl ; cout << "Enter your height in inches " ; cout << "(No fractions, please!) : " ; cin >> height; cout << "Enter your weight in pounds" ; cout << "(No fractions, please!)" ; cin >> weight; cout << endl ; double metric_height = height*INCHES_PER_METER; double metric_weight = weight/POUNDS_PER_KG; cout << "Your height is " << metric_height << " meters." << endl; cout << "Your weight is " << metric_weight << " kilograms." << endl; return 0; }

Step 3:

As you are entering the program text, you should save the file in one of several ways; e.g., either click the "disk" icon on the toolbar, or select "File->Save As...". When you choose a name for your program, use a ".cpp" suffix to indicate it is a C++ program, for instance "metric.cpp". Navigate if necessary to the testproject folder and save your file there.

Step 4:

Notice that after saving the file with the ".cpp" suffix, syntax highlighting is in effect.

What do you suppose the significance is of blue-colored text and green-colored text? Record your answer on your lab sheet.

4. Compiling, Linking, and Building your Program

Your next step is to compile the program. This translates your C++ code to machine language so that the machine can understand what steps it must follow.

Step 1:

First, tell Visual C++ that the program you have just created should be installed in your project. Do this by choosing Project->Add to Project->Files..., then navigate to your "metric.cpp" file in the testproject folder. Select metric.cpp and click "OK".

Step 2:

To compile, build, and run your program, you can either choose commands from the Build menu or select their equivalents from the toolbar: . You can learn what each icon stands for by positioning the cursor over it and waiting (without clicking!) for a moment until a short description appears below your mouse pointer. Determine the meanings of these icons and record them on your lab sheet.

Step 3:

Now that your program has been installed in the active project, you are ready to try to compile it. Do this by selecting Build->Compile metric.cpp (or by clicking the Compile button in the toolbar).

If all goes well, you should see the following text in the message window at the bottom of the screen:

--------------------Configuration: testproject - Win32 Debug--------------------
Compiling...
metric.cpp
metric.obj - 0 error(s), 0 warning(s)

However, if you typed in something incorrectly, you may receive one or more error messages. If the compiler cannot understand what you meant, it tries to diagnose the error. Unfortunately, compilers cannot always tell you what your mistake was. Rather, a compiler can show you the point in the code where it first detected a mistake. Sometimes, the error has occurred elsewhere in the code before that point.

Sometimes, you may receive MANY error messages because of one small error earlier in the program. (This happens, for instance, if a variable is declared in the beginning of the program, then used in many places throughout the program. If the name was misspelled in the variable declaration statement, the compiler will deem every subsequent usage of that name throughout the program as incorrect.)

If you do get error messages, record the first error message on your lab sheet. Determine what the error was in your source code, and correct it. Explain the error on your lab sheet.

Continue this process until the program runs correctly. You must repair every syntax error before you can continue.

Step 4:

When you reach this point, your program should have compiled successfully. If not, return to the previous step. Now you are ready to build your program. It may seem like you are going through a lot of unnecessary steps here, but the reason is that programs can contain many separate files, precompiled libraries, and so on. Although our program is simple, the compiler needs to be ready for such a situation. Building your program can be accomplished by selecting Build->Build testproject.exe (or by clicking the Build button in the toolbar).

If all goes well, you should receive a message

--------------------Configuration: testproject - Win32 Debug--------------------
testproject.exe - 0 error(s), 0 warning(s)

On your lab sheet, indicate whether this program compiled with no errors. If errors exist, you must correct them before proceeding further.

5. Running your Program

Step 1:

Now you are ready to run (or execute) the program. Do this by selecting Build->Execute testproject.exe (or by clicking the Execute button in the toolbar).

If all goes well, a console window will appear, containing the results of the program, as in the sample run shown below:

Step 2:

You should see a prompt asking for your height in inches. Respond by typing your height, followed by the Enter key. After you respond, you should be prompted again for your weight in pounds. Enter a value for this, again following with the Enter key. The text that is printed next should contain metric conversions of these measurements.

If you do not get the desired results, there may be a problem in your program which was syntactically correct but semantically incorrect. That is, your program had the appropriate form, but the instructions meant something other than what you intended. (The difference is similar to the difference between typing "there house" or "they're house" instead of "their house"; a spelling checker would not detect the error, but the first two expressions are incorrect; or the "Dog bites man." vs. "Man bites dog." examples from lecture).

Carefully check your program for unexpected or incorrect results. This program has been crafted with a deliberate error, so you should find at least one! If you find an error, try to determine what caused it. Be sure to compare your program with the one above - you may have introduced even more errors by not typing the program in correctly.

Please note: If you find the command prompt disappears immediately after execution instead of staying open, you can change this behaviour of automatically closing the command prompt window. If you choose Debug → Start Without Debugging (or press Ctrl + F5), a "Press any key to continue" statement is added by Visual Studio and prevents the command window from automatically closing before you are able to view the program output. If, instead, you select Start from the Debug menu, then the application runs, but the command window automatically closes at the end of program execution, unless you set a breakpoint on the last line of the program.

On your lab sheet, record any errors that you may have found, and attempt to correct them.

6. Saving your Output

One of the greatest deficiencies in Visual C++ is that there is no simple way to save the results of your program run in a console (DOS) window. One way you can save a copy of the text in the console window is by copying it and pasting it into a document in a text editor.

Step 1: Open a text editor program, such as Notepad or WordPad.

Step 2: Click your testproject output window so it is active. Then, position the cursor in the output area and click and drag over all text you wish to select (Note: you might have to click the "mark" icon or choose it from the Window-Menu).

Step 3: Hit the Enter key (or, you might have to click the "copy" icon to copy the text to the clipboard).

Note: Visual C++ may be slightly different depending on the machine that you are using. The "mark" and "edit" buttons may not be available on your display. Instead, you will find them as options under the "Edit" menu. That is, you will select Edit --> mark and Edit --> copy from the menu across the top of the window.

Step 4: Return to the text editor program, then choose Edit->Paste in order to copy your text from the clipboard to a file. Save your output using the "File->Save As..." command.

Step 5: Return to your testproject output window so it is active, and terminate your program run by typing any key.

Print a copy of your output and attach it to your lab sheet.

7. Dealing with Errors

Diagnosing and correcting syntax errors can be a daunting process for the uninitiated. For this reason, we will introduce deliberate errors and learn what sort of error messages are produced by them.

Step 1: Return to your source file in the Visual C++ environment.

Step 2: Modify your file and put an intentional error: remove a necessary semicolon. Run the program again. Because Visual C++ is aware you made changes to your source code, it will try to recompile and relink.

Step 3: You should have gotten a compile-time error message. Compare what the error message says to what the problem really is. (You may have to scroll up in the "Build" window in order to find the actual error message.) Not all error messages are very accurate or descriptive. Double clicking on the error message will cause a blue bullet to appear in the source window to the left of the line of code where Visual C++ thinks the error exists in your source code. Fix the error, but try other kinds of modifications (one at a time) and see what happens. In each case, enter the results on your lab sheet:

Try 1: Delete a line declaring a variable -- What is the output?

Try 2: Remove a "//" from the beginning of a comment line.

Try 3: Add a "//" to the front of the int main(void) line, turning it into a comment.

Try 4: Delete the line containing the compiler directive #include

Try 5: Change the constant 2.24 to 100.0

Try 6: Change the spelling of height to hight in the declaration line "int height;"

Try 7: Change the spelling of metric_height to metric_weight in the output line

cout << "Your height is " << metric_height << " meters." << endl;

Try 8: Change one of the const double declarations to const int.

EVALUATION: Which of the errors in the previous step were syntax errors and which were semantic errors? Enter the answers on your lab sheet.

8. Summary

In this lab, we have covered the basics of programming in the Visual C++ environment: creating a workspace, entering a program, adding the program to a project, compiling, building, and executing a program, saving your results, and diagnosing errors. These skills are necessary in order to program successfully. Subsequent labs will expect you to know how to do these things, and deal more with the C++ language than with the Visual C++ environment.

You may wish to consult with this lab in the future when you have difficulty using the Visual C++ environment.

Hand In: This lab handout with the answers filled in attached to a listing of your output