CS1110 Fall 2008 Assignment A3 Monitoring Rhinos 2
Due (submitted on the CMS) by Monday, 29 September
This assignment continues with A1. Start with your A1
classes Rhino and RhinoTester, which should be correct. You
can group all your test cases for this assignment in one test
procedure.
Keep track of the time you spend on this assignment. When
you submit it, tell us how many hours you spent on it.
You may work in groups of 2, but you must do all the work together, sitting at the computer together. For
example, for one person to write functions and the other person to write test cases for them, with no
interaction, is dishonest. If you want to form a group, do it immediately. Both partners must take action in
the CMS before the group will be formed.
The deadline is Monday, 29 September, so that it is completed before the first prelim. Because you have a
lot of work to do, including studying for the prelim, we have considerably reduced the work involved in this
assignment by removing 5-6 functions from previous years.
In assignment A1, if you made a mistake, we asked you to fix it and resubmit. In this assignment, if you
make a mistake, points will be deducted. Points may be deducted for lateness. Your new functions must
have suitable javadoc comments, there must be appropriate test cases, and all methods should be correct.
You can achieve all this most easily by writing and testing one method as a time.
In this assignment, you will add to the class Rhino of A1: (1) a static variable and (2) more comparison
methods, using boolean expressions.
The steps to perform in doing this assignment
Step 1. Static variable. Add to class Rhino a private static variable that contains the number of Rhino
objects that have been created so far. WHENEVER A RHINO OBJECT IS CREATED, THIS FIELD
SHOULD BE INCREASED BY 1. Provide suitable test cases.
Add a static int function getPopulation, with no parameters, that will return the value of the static
variable. Change the constructors so that they properly maintain the value of the static variable. Finally, add
test cases to class RhinoTester to test whether the static variable is properly maintained.
Step 2. Comparison functions. Write the following functions, all of which produce a boolean value. Do
one at a time: (1) write the function, then (2) test it thoroughly with test cases in class RhinoTester. Then
proceed to the next function.
Method Description
isMotherOf(Rhino r) = "r is not null, and this rhino is r's mother".
isFatherOf(Rhino r) = "r is not null, and this rhino is r's father".
isParentOf(Rhino r) = "r is not null, and this rhino is r's parent".
isBrother(Rhino r)
= "r is this rhino's brother". Precondition: r is not null. Note: r is Rhino A's
brother if (1) r and A are two different objects, if r is male, and if r and A
have at least one parent in common.
