Question

The instructions say:
Create an equals method that takes an object reference and returns true if the given object equals this object.
* Hint: You’ll need ‘instanceof’ and cast to a (Position)

I have:

class Position {

    private double x,y;
    private int id;

public boolean instanceOf(Object a)
    {
        boolean isInstance;
        if ((Position)a instanceof Position)
            isInstance=true;
        else
            isInstance=false;
        return isInstance;
    }

But I’m doing it wrong, and I dont know what my problem is. I’m new to objects so this is kind of confusing me..

Answer 1

As this is a homework question, I won’t give a detail answer.
You have to implement a equals() method, not a instanceOf() method. I think this link help:

• http://www.ibiblio.org/java/course/week4/37.html
• http://www.billthelizard.blogspot.com/2008/08/implementing-equals-in-java.html

The code example in them should be sufficient. Ask again if you need more hint.