My First Eclipse Experience (Fall 2008 Edition, for CSc 102)

 

This is a quick tutorial on how to get started with the Eclipse C++ Integrated Development Environment (IDE).

 

This presentation is entirely tied to my lectures in CSc 102, Introduction to Computing, at City College of New York in Fall, 2008. Even more particularly, it is the technical part of what I do in the first lecture of the semester, on August 28, and what the lab instructors may do in the first lab, on August 29.

 

At home . . .

 

In the lab you don't need to do the first four steps; Eclipse is installed.

1.      Point your Web browser at: http://www.eclipse.org/downloads/  Click on the link Eclipse IDE for C/C++ Developers (68 MB), and choose Windows. Choose a mirror site; Columbia is nearby, but any other http site will do.

2.      You will be asked whether you want to Open the downloaded file or Save it. Choose Save, and click on OK. You will be asked where you want to store the compressed (ZIP) file. Save it to a folder on your C: drive. Why not call it EclipseC++? But that’s up to you

3.      Right-click on the Eclipse file name (eclipse-cpp-ganymede-win32.zip), in the folder you just created. Pull down to WinZIP. Click on Extract to Here. That will get you a folder named Eclipse; click on it. Finally, when you are ready, click on the file named Eclipse.exe. This is what is meant by “clicking on the file name” in step 5 below. Your mileage may vary! This step doesn’t always work the same way even on my machine. Mouse around; try reasonable things. It’s a very simple installation, compared with some software.

4.     You need to create a “workspace” for Eclipse. Put it in your CS102 folder; call it anything you please. I named mine WorkspaceForTutorial.

5.      Everything else is identical to what you do in the lab. Pick up with Step 7 below.

 

In the lab . . .

  1. You need to create a “workspace” for Eclipse. Put it in a folder in C:\TEMP; call it anything you please. I named mine WorkspaceForTutorial. Everything about loading Eclipse has been done for you; just click on the desktop icon to launch Eclipse.
  2. When you click on the eclipse.exe icon or file name, you will first see (briefly) the image shown in Fig.1. “Ganymede” is the code name for the 2008 version of Eclipse. (Ganymede is the largest moon of Jupiter; previous versions of Eclipse were named Calisto and Europa, two other moons of Jupiter.)

Fig. 1. The first thing you see when you launch Eclipse. This disappears after a few seconds.

  1. When the window of Fig. 1 disappears, you will be taken to a dialog like that in Fig. 2. A default workspace address is shown, but we don’t want that. Click on Browse and navigate to the workspace you just created. Click on OK.  (Actually, I'd suggest you first create a folder in C:\temp (or wherever you want on your own machine) named 102HW1 or whatever, and specify that when you start Eclipse. Before long you are going to have lots of saved workspaces; put them somewhere you can find them, and give them names that mean something to you.)

Fig. 2. The Workspace Launcher dialog that you get when you open Eclipse. The address shows the result after I browsed to a workspace on my hard drive.

  1. Up comes the welcome screen; see Fig.3.

Fig.3. The Eclipse welcome screen.

  1. The icons at the left on this welcome screen (which you see only when you launch Eclipse with an empty workspace) are as shown in Figs 4a, b, c, and d. Explore them if and when you wish. Not needed to get the first assignment done.

Figs 4a, b, c, d.

 

  1. The icon on the far right says to go to work. See Figure 5.

Fig 5. Get to work!

  1. After clicking on the Workbench icon or in the far top-left tab, you will see a blank Eclipse workbench. See Fig 6. Your screen layout may be slightly different. Not a problem. You may or may not see an Outline View on the far right. If you do, click on the X in its title bar is dismiss it. We don't need it for this exercise.

Figure 6. The Eclipse workbench.

  1. Create a project: File/New/C++ Project. Click on Next. Name it Lab1, or anything else you please. Leave all selections as they are, and click Finish. See Figures 7 and 8.)

Figure 7. Creating a C++ project.
 

Figure 8. Continue creating a C++ project.
 

11b. If you click on Next instead of Finish, you will see this; just click Finish:

Fig 11b. The Select Configurations dialog. Ignore; just press Finish.

  1. Right-click on the Lab1 name in the Project Explorer. Click on New, then Source File. See Figure 9.

Figure 9. Creating a new source file.

  1. You will be asked to give the new source file (your program) a name. Your choice. I called it MyFirst.cpp. Note the cpp file extension, which you must type. (It means C++.) Click Finish. See Figure 10.

Fig 10. Naming your new source file.

  1. The editor window will show a C++ comment giving basic documentation. Change “Dan” to your name, or, if appropriate, your team number and names of your team members. See Figure 11. Always do this!

Fig 11. The opening editor window. Change the “Dan,” unless that is your last name!

 

  1.  Copy the following text to the editor, below the comment. Select all the text; press Control-C (copy); move to the editor window; position the cursor below the comment; press Control-V (paste)

#include <iostream>
using namespace std;
 
int main()
{
     cout << "Hi, Mom!" << endl;
 
     // Compute and print the sum of the first ten integers
     double sum = 0;
     for (int i = 1; i <= 10; i++)
          sum += i;
     cout << "The sum of the integers from 1 to 10 is: " << sum;
 
     return 0;
}
 

 

We’ll talk about this a bit later; for now, let’s just watch it run. Figure 12 shows what your editor window should look like now.

Fig 12. The editor window after you copy the program text shown just above.

 

 

  1.  Let’s say you have a little trouble reading the editor window on your machine. Let’s make the font bigger.

 

Fig 12. The Preferences window, under Window.
 

Fig 13. The Preferences window after typing” font” into the text box at the top left.
 

Fig 14. The font selection window, which we get by double-clicking on As C++ Editor Text Font etc., or by clicking on As C++ Editor Text Font etc then clicking on Change. You often have this kind of choice. Double-clicking is faster.

  1. Compile and link your program by clicking on Project and pulling down to Build Project. If there are no errors in the program, and I don’t think there are, you will get a brief message saying Build complete for project Lab1, and giving the time the process required. (Ignore the rest of the message for now.)
  2. Run your program by clicking on Run and pulling down to Run. Eclipse will check to see if there have been any changes since you last compiled and recompile if so. Either way, the program will run, with output:

    Hi, Mom!
    The sum of the integers from 1 to 10 is: 55

     
  3. That is your introduction to Eclipse. Don’t be discouraged if it seems like slow going. In a week or two you will be able to do all the steps of this tutorial in a couple of minutes. Really.

 

  1. This program uses small pieces of the first two chapters of the text. But we can understand the basic ideas. Let’s look.
  2. #include <iostream> is a preprocessor directive. It says to bring into our program a large body of code that handles input from the keyboard and output to the console. That’s really about all we have to know, for this course. (There is no semicolon at the end of this line.)
  3. using namespace std; (note the semicolon) says names like iostream will come from a standard collection of names. Just do it; there will be more about this later in the course.
  4. int main() says that main is a function, and that it returns an integer. The parentheses are required; in many cases the parentheses will contain information about data to be processed by the function. Every program must have a main function somewhere; it’s where program execution begins.
  5. The left curly brace on the next line denotes the beginning of the body of the main function. The curly right brace at the end of the program “closes” body, and is required. (The curly brace will be at the end of the line above, with the default Eclipse settings. You can change that—although I don’t know how at the moment.)
  6. cout is how we print output to the console. There is lots of talk in the text and later in the course about what all can be written in a cout statement. Our output is a modified version of the first example in any programming language: Hello World! (cout is pronounced "See Out.")
  7.  Next we have a comment, signaled by the two slashes. This conveys no information to the compiler; it is for the benefit of the (human) reader of the program.

    IF YOU DON'T UNDERSTAND THE NEXT THREE STEPS, DON'T WORRY ABOUT IT! I'M AHEAD OF THE TEXTBOOK.
  8.  double sum = 0; is a variable declaration. It says that sum is associated with a place in computer memory where a certain kind of number can be stored. sum is initialized to zero.
  9. The   for (int i = 1; i <= 10; i++) says to declare an integer variable i and initialize it to zero; execute the statement on the next line as long as i is less than or equal to 10; add 1 to i each time around.
  10.  sum += i; says to add the value of i to sum.
  11. The cout does what it says it says it does.
  12. The curly right brace marks the end of the body of the main function and the end of the program.
  13. You’re done! When you are ready, tackle Homework 1 (HW1). You know just about everything needed to do it, with the help of Chapters 1 and 2 of the text.
  14. But if you don’t fully understand the program please don’t worry about it! The for loop in particular will get considerably more exposition in a couple of weeks.

 

 

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