Java Homework Assignment : Classes Racing Report CSS 161 Fundamentals of Computing

Summary

You will write a racing report program using object-oriented programming with three classes: ReportDriver, RaceReport, and Race. The main method of the program will be in the class ReportDriver and will include a loop that allows you to enter in more than one race and have reports written out for all the races you enter. (The user will enter one race then get a report for that race. After that, the user will be asked whether they want to enter in another race and get another report. This repeats until the user says they do not want to enter in any more races.

Program Description

There are two major tasks in this assignment. Your first major task is to write a program that collects three pieces of user input about a race and provides a summary of facts about the race. Input will be via the keyboard and output (i.e., the summary of facts) will be via the display (a.k.a., console window). The three pieces of user input will be the three individual race times that correspond the first, second, and third top race finishers; your program will prompt the user to enter these in via the keyboard. Note that you cannot assume these times will be in order; putting them in order is one of the first things your program should do. Thus, your program will need to do the following:

1. Prompt the user for three ints or doubles, which represent the times for the three racers. 2. Sort the three scores into ascending order (i.e., least to greatest).

(a) Remember, to swap two variables requires a third, temporary variable.

(b) See the Math class (documented in Savitch Ch. 5; see the index for the exact location . . . this is good practice for looking things up) for methods that might help you (e.g., min and max). Note that these methods produce a return value.

(c) Output the sorted race scores in order. 3. Describe the overlap in times, if any exist. The options will be:

(a) All are tied for first. (b) Some are tied for first. (c) None are tied for first.

4. Do step (4) for the second and third place finishes. 5. Output the range of the race scores. 6. Output the average of the race scores.

There are, of course, many different ways of writing this program. However, if you decompose your tasks into smaller chunks, attacking a larger program becomes more manageable. If you mentally divided up the tasks before you, you might have decided on the following list of work items, chunks, or modules:

Data Input: Ask the user for three race scores (in no particular order). Ordering Data: Order the race scores by first, second, and third place. Data Analysis and Output:

Determine how many racers tied for first, second or third place (i.e., how many overlap times) and output result to console.

Calculate the range of the race scores (i.e., the absolute value of the slowest minus the fastest times) and output result to console.

2

Calculate the average of the race times and output result to console.

The second major task in this assignment is to take the functionality of the program described above and divide it up into blocks of tasks that can become methods and to create the infrastructure (e.g., declaring and setting instance attributes, creating accessor and/or mutator methods, making sure all the classes can work with one another, etc.) to implement your earlier program in an object-oriented way.

What might be some of the methods that you will create? Here are just as few from one possible solution (it does not include all the methods from that solution). Again, remember that there are many valid ways of writing this program; you may or may not want to create any of these methods, but you will almost certainly need to create more than these methods. This list is just to give you an idea of how one might be able to restructure the functionality described above into an object-oriented structure:

In the Race class:

readIntimes sortTimesAscending ... and other methods ...

In the RaceReport class: A writeReport method. In the ReportDriver class: There is only a main method. (If you have other methods

here, such as a test method, thats okay, but if you dont, thats okay too.)

(Dont forget to create constructor and other methods, if appropriate.)

Your program is required to exactly reproduce the format and behavior of the sample execution below (note how the user is asked to continue if desired):

Enter the race times (in seconds): 85.6 120.5 90.2 

First place (time in seconds): 85.6 Second place (time in seconds): 90.2 Third place (time in seconds): 120.5 

The range of the race times (in seconds): 34.9 The average time of all racers (in seconds): 98.77 

Enter another race? (y/n): y 

Enter the race times (in seconds): 114

First place (time in seconds): 1.0 Second place (time in seconds): 1.0 Third place (time in seconds): 4.0 

3

Two racers shared first place. The range of the race times (in seconds): 3.0 The average time of all racers (in seconds): 2.0 

Enter another race? (y/n): n 

I expect you to make appropriate choices about variable types and which variables are class variables and which are local to a method. The private data (attributes) of any class should only be the data directly associated with being that kind of object. Thus, the private attributes of Race should only be the data associate with being a race. Any other variables that help in performing the tasks (i.e., the methods) should be local (i.e., defined within the method).

Finally, there should be at least one method that you write that can be used to provide output for tracing variables: The method should be called test-something, e.g., testStatistics. Somewhere in your program, there should be a call to that method. In the code you submit, that call should be commented out, but I should be able to find it.