M/F 2:30-3:20   
in G01 Gates Hall

CS 1130: Transition to OO Programming

Spring 2016

Self-Help Exercise

Including Partition Object when Drawing Objects

This self-exercise is to include a partition for class Object when drawing objects. Here are the answers, in a pdf file.

Exercises

Step 1. Draw an object.

Consider the following classes:

public class Ex {
    public static final int ZERO= 0;
    private int h;

    public Ex(int ph) {
        h= ph;
    }

    public int getH() {
    return h;
    }

    public String toString() { ... }

    public static int what(int x) { ... }
}

public class Sub extends Ex {
    private int k;

    public Sub(int pk) {
        k= pk;
    }

    public String toString() { ... }

}

To the right is an instance of class Sub. Below the horizontal line are all the instance variables and methods that are declared in Sub; above the line are all the instance variables and methods that are declared in superclass Ex. Variables h and k have been given arbitrary values.

On your paper, draw an instance of class Ex and another instance of class Sub; this time, include in each object you draw the partition for class Object.

Step 2. More subclasses

Consider also these two subclasses of class Sub:

public class SubSub1 extends Sub {
    public SubSub1() {
        super(5);
    }

    public int hPlus1() {
    return getH()+1;
    }

    public String toString() { ... }
    }

public class SubSub2 extends Sub {
    private int p;
}

Draw an intance of class SubSub1 and an instance of class SubSub2; this time, include in each object the partition for class Object.