CS100, Spring 2000, Exercise 5: Don't Box Me In!
Due at the beginning of lecture on Tuesday, March 7 


Name: ____________________________________________________________________

  ID: ____________

Concepts

    + Class definitions, objects, references, null, instance variables.
    + Declaration versus initialization versus instantiation/allocation.
    + Box diagrams.

What to turn in: 

    A printout of this exercise with your answers legibly HANDWRITTEN.

===============================================================================

(a) Fill in the blanks and boxes below to match the comments.

// REFER TO PROJECT 4 ON THE CS100 WEBSITE!
// For this exercise, you're using a miniature version of Project 4's
// $Parthon$. Although on Project 4 you will want to use multiple variables,
// create this family tree without using any more variables. Each
// $Parthon$ now has only a $name$ and a $parent$:

class Parthon {

    ________________________________________ ; // name of the Parthon

    ________________________________________ ; // parent of the Parthon
}

public class Exercise5 {
    public static void main(String[] args) {
    
	// The following declaration provides the only variable we
	// want you to use:
           Parthon ur;

        // Create this family tree without using any more variables
        //
        //         Ani
        //          |
        //          |
        //         Naj
        //          |
        //          |
        //         Ur
        //
	// So, your code will have no $Ani$ or $Naj$ variables!
        // HINT: $ur.parent$ should prove useful at some point

            +-----------------------------------------------------------------+
            |                                                                 |
            |                                                                 |
            |                                                                 |
            |                                                                 |
            |                                                                 |
            |                                                                 |
            |                                                                 |
            |                                                                 |
            |                                                                 |
            |                                                                 |
            |                                                                 |
            |                                                                 |
            |                                                                 |
            |                                                                 |
            |                                                                 |
            |                                                                 |
            |                                                                 |
            |                                                                 |
            +-----------------------------------------------------------------+

        // ******* draw the Box diagram for this point in the program *******
	// (See Part b for an explanation of what you need to do.)

    } // method main

} // class Parthon

===============================================================================

(b) Draw the requested box diagram for the state of the computer
    at the *precise* point specified above in Part a.
    We have already drawn for you all the String objects that are needed.

class Exercise5     class Parthon 
+---------------+   +---------------------------------------------------------+
|               |   |                                                         |
|  main(args)   |   |                                                         |
|  +---------+  |   |                                                         |
|  |         |  |   |                                                         |
|  |         |  |   |                                                         |
|  |         |  |   |                                                         |
|  |         |  |   |                                                         |
|  |         |  |   |                                                         |
|  |         |  |   |                                                         |
|  |         |  |   |                                                         |
|  |         |  |   |                                                         |
|  +---------+  |   |                                                         |
|               |   |                                                         |
+---------------+   |                                                         |
                    |                                                         |
class String        |                                                         |
+---------------+   |                                                         |
|               |   |                                                         |
|  "Ur"         |   |                                                         |
|               |   |                                                         |
|  "Naj"        |   |                                                         |
|               |   |                                                         |
|  "Ani"        |   |                                                         |
|               |   |                                                         |
+---------------+   |                                                         |
                    |                                                         |
                    |                                                         |
                    |                                                         |
                    +---------------------------------------------------------+