HW03: Arrays of Objects due Mon 06 Feb 10:00

Instructions

For this assignment you will modify the movies program we have been working on so that instead of having three parallel arrays you will have a single array of Movie objects. In this assignment you will make this change and get all parts of the program to work with the new arrangement.

You have already created a functional Movie class and have written a useful constructor and toString() method and so are well on your way.

Steps to Work on Before Friday

1. Take a moment to read the sample code and commentary in the section called “Arrays of Objects (non-OOP)” found in the CSCI 2320 Command Sheet (with commentary) document. Keep this code handy for the following steps.

2. Copy your working movies program from hw02 into hw03. You should rename it to something like ArrayOfObjectsMovies.java to indicate how it will be different from the original. All of the remaining steps are to be taken in the new program.

3. In main() delete the three parallel arrays and replace them with one array of Movie objects. Doing so will cause large portions of your program to stop working. Be sure to reserve 10,000 slots for the new array.

4. In main() comment out all the method calls that pass the (original) three parallel arrays as parameters. Get the program to compile with those method calls commented out.

5. Turn your attention to the loadMovies(). Modify the parameter list so it takes only one parameter: an array of Movie objects. Temporarily comment out the body of the method so your method looks something like this:

   public static int loadMovies(Movie [] movies) {
   
   	// new (temporary) code goes here
   
   /*
   all the original code is commented out here
   and pushed to the bottom. We'll deal with it
   later.
   */
   }
   

6. Add new (temporary) code to loadMovies() that will (manually) create five new movie objects and make the array refer to them. The method should return the value 5 since there will be 5 entries in it. Something like this:

   movies[0]= new Movie("Up", "Animation", 2005);
   // four more movies go here
   return 5;
   

7. Modify the displayAll() method so it takes two parameters (an array of Movie objects and the number of elements in the array). Then modify the body of the method to display the elements of the array. Remember, since you have written a toString() method you can print the first movie simply by do this:

   System.out.println(movies[0]);
   

8. Once the program is putting 5 elements in the array and then displaying the array take a moment to update your documentation for loadMovies() and displayAll().

9. Commit and push your work.

Steps for Friday and Following

• The documentation of most methods will need to change to reflect the fact that you will be passing only one array to the methods rather than multiple arrays. Since the documentation of parameters will be the same for many of the methods this would be a good place to make use of the ancient, but effective, copy-paste technology.
• Likewise the parameter lists of many of the methods is identical. Copy-and-paste! NOTE: But don't copy-and-paste until you have a working, tested, and committed parameter list to start with!
• Continue the pattern we've established of committing often.
• When you finish remember to push your work to your homework repository.
• Also, it is traditional for a conquerer to engage in trash talk when completing a conquest.

Grading

Your program should be completely working and should follow all of the programming conventions named in class and explained in http://josephus.hsutx.edu/classes/all/javaconventions/ (including the use of comments that conform to the JavaDoc guidelines).

The instructor will grade your work based on what you have pushed to the hosted homework repository you have shared. For all assignments the program is due before the beginning of class on the due date. Repositories that show a commit time after that time will be graded as late.