CPE 101:
Fundamentals of Computer Science 1

Writing and compiling Java programs will be covered in lab during week #1. Using the "handin" process that you must use to submit this assignment will be covered in the first lab session of week #2: all course participants must have obtained their Central Unix account by the start of our lab during the second week.

Here again is a link to an explanation of the handin process you must use to submit your programming assignments to me.

Start with either your assignment template, that you created in Lab 1, or download another copy of my Template1 and re-enter all your own personal information. Then, for each program described below, make a copy with the appropriate changes. For example, for the first part below, you'd save it as SimpleMath.java and, when prompted to make the other necessary changes, you should do all of the following:

1. Change the ClassName on line 2 from template1 to SimpleMath
2. Change the Assignment description on line 3 to Program 1.1, A Simple Math Program
3. Change the class name on line 48 from template1 to SimpleMath

Then, when you start the second program below, start with the template again, and make the changes necessary for it. You'll find reminders about these steps throughout this assignment, and only this one, but you should follow a similar process for every program you write for this course.

The first program is due by 9 p.m. Friday. FOR THIS ONE PROGRAMMING PART (and ONLY this programming part, Pgm1a) you are allowed to work with a partner if you wish, but you MUST note that on your program documentation, including the nature of the help given and the name of the partner.

• follow a set of program specifications,
• write your first Java program from scratch,
• document it, and
• accomplish all the other tasks (e.g., ftp & handin) you need to submit it.

First, practice writing some simple Java applications using arithmetic expressions.

• Start with a copy of your new template file. Save a new file from that, named SimpleMath.java (use exactly that name, capitalization and all).
• Make appropriate changes to this file right away (e.g., change the actual class name and the reference to the class name in the comment block, and fill in the other information relevant to this assignment).
• Modify the program block to do the following things. Take them one at a time (i.e., save, compile, and execute the program after each step, and resolve any problems, before moving on to the next step), and add appropriate documentation (as needed, to both the header block and to individual segments) as you go:
  • Declare three integers (x, y, and z) initialized to a given set of values (5, 8, and 25, respectively). Compile and execute. You shouldn't yet see any output, but you should not move on until you have eliminated any errors you may find!
  • Print the variables and their value. Use one line for each. That is, print x = 5 on one line, y = 8 on the next, etc.
    • Do not "hard code" the values. That is, the "x = " should be printed literally, but the value (currently 5) should result from your actually printing the value of the variable x.
    Compile and execute. Check that the output is correct.
  • Add a statement that prints a blank line before any additional output is displayed. Compile and execute. Check that the output is correct.
  • Add a statement that first labels and then presents, on the next line, the sum of x and y. (At the minimum, your program should print out, x + y = 13 but, even better, you could display x + y = 5 + 8 = 13 where, once again, the x and y are printed literally but all the numbers must be from the variables themselves.) Compile and execute. Check that the value is correct.
  • Add a statement that first labels and then presents, on the next line, the product of x and z. Compile and execute. Check that the value is correct.
  • Add a statement that first labels and then presents, on the next line, the difference between y and z. Compile and execute. Check that the value (including the sign) is correct.
  • Add a statement that first labels and then presents, on the next line, the value of the expression y/x. Compile and execute. Is the value what you expected? Do both of the following:
    • Note this in your course notebook, and
    • add a comment to this program reflecting on whether or not this is what you expected and, if not, if you now understand it or if you still have questions.
  • Add a statement that first labels and then presents, on the next line, the value of the expression y % x. Compile and execute. Is the value what you expected? Once again, note this in your course notebook and in a comment in your program.
  • Add a statement that first labels and then presents, on the next line, the value of the expression y + z / x. Compile and execute. Check that the value is correct.
  • Add a statement that first labels and then presents, on the next line, the value of the expression (y + z) / x. Compile and execute. Compare this result with that of the previous step, and either confirm that the value is correct or resolve any discrepancies that you notice. Note this in your course notebook and in a comment in your program.
  • Add a statement that first labels and then presents, on the next line, the value of the expression (double) (y + z) / x. Compile and execute. Compare this result with that of the previous step, and either confirm that the value is correct or resolve any discrepancies that you notice. Once again, note this in your course notebook and in a comment in your program.
  • Add one final statement of your own choosing that does something interesting with the variables x, y, and/or z. Compile and execute. Add a very brief comment to your code explaining (in English, not Java) what this statement does and why it's interesting.

Make sure you save this program when you are done. Continue with the next part of this lab. When you get to the end, you'll find instructions on how to hand in this source code file for grading.

The remaining program is due by 9 p.m. Sunday. You may, of course, submit the last program at the same time as you submit the first one (using the appropriate handin folder for each set), but I'm splitting this assignment into two parts because I want everyone to get started using handin during the week (rather than waiting until the weekend, when less support is available for anyone having difficulty...).

The challenges here are to successfully:

• follow a set of program specifications,
• convert from one set of Java commands (java.util.Random) to another (Math.random),
• explore some of the issues related to data types and mathematical operations,
• continue to practice documentation, and
• continue to accomplish all the other tasks you need to submit your work.

For our last program, we will develop a very simple, text-based "dice roller" game. Each time you play this game, a pair of six-sided dice are rolled (but write your program such that those numbers can be easily changed in future versions; i.e., use variables with meaningful names for both the number of die pieces and number of sides on each one). Your program is to print out a message indicating the face that appeared (randomly, of course) on each individual die, and the total number of points for the roll.

While you won't be given directions on exactly how to write design this, as you were for the first part of this assignment, all of the following are required for this program:

• It must be called TwoDice.java
• Some sample runs might look like the following:
  • >java TwoDice
    Die #1 shows 1 and Die #2 shows 1.
    Your total roll is 2.
  • >java TwoDice
    Die #1 shows 3 and Die #2 shows 6.
    Your total roll is 9.
  • >java TwoDice
    Die #1 shows 2 and Die #2 shows 5.
    Your total roll is 7.
• The top of the template must be filled in with full details.
• The program must follow the style guidelines in textbook Chapter 2.
• Good use of indentation, line spacing, and additional comments must be apparent.

For this and all future programming assignments, you will submit your source code files (and, unless explicitly told otherwise, only those .java files) via the Central Unix Handin facility. It is recommended that you first try submitting a file or two to the Test folder, to familiarize yourself with the process (although work submitted there will NOT be graded). Once you think you understand the process, then submit these files as noted:

• to the Pgm1a folder (which will close at 9 p.m. on Fri, April 11):
  • SimpleMath.java
  
  
• to the Pgm1b folder (which will close at 9 p.m. on Sun, April 13):
  • TwoDice.java

Please Note: Only programs that we can compile successfully in our lab environment will be graded. (Compiling in your, possibly different, environment is not adequate. They must compile in the CSc Lab.) Programs that do compile, but contain errors, may be eligible for partial credit if and only if you make it clear that you are aware of the program's limitations by documenting all problems you know about and the things you have tried, unsuccessfully, to fix them. You may document this in one of two ways:

• in the comment block at the top of your program, under a Pending Problems category, or
• in a text-only README file that you submit along with your program, and reference in the Pending Problems section of the program's comment block.