Access superclass fields

Question

For example I have abstract class Shape, that gets the coordinates of the shape:

public abstract class Shape{
    private int x;
    private int y;

    public Shape(int x, int y){
        this.x=x;
        this.y=y
    }

    public abstract void onDraw();

}

Now I have the class Rect the extends from Shape:

public class Rect extends Shape{
    private int height;
    private int width;

    public Rect(int height, int width){
        this.height=height;
        this.width=width;
    }

    @Override
    public void onDraw(){
        //this method should get the width and height and the coordinates x and y, and will print the shape rect
    }
}

Now my question is: how can I get the coordinates x and y of the abstract class Shape from within Rect?

please follow the naming conventions – Philipp Sander Feb 25 '14 at 14:19 — Philipp Sander, Feb 25 '14 at 14:19

score 7 · Accepted Answer · edited May 23 '17 at 10:31

7

You can't get them as long as they are private. make them protected instead.

More information can be found here.

edited May 23 '17 at 10:31

Community

1
1

answered Feb 25 '14 at 14:19

exception1

1,239
8
17

1

Also the constructor for class rect should be called rect(), not shape(). – jgitter Feb 25 '14 at 14:20
Or make getter methods for them... – Luiggi Mendoza Feb 25 '14 at 14:23
Making getters/setters in the abstract class will make the variables accessable in every other subclass, what he might not want. Ig he only needs `x` and `y` in `onDraw()` then making getters in not necessary. – exception1 Feb 25 '14 at 14:28

score 6 · Answer 2 · answered Feb 25 '14 at 14:21

simply make some getters for them:

public abstract class shape{
    private int x;
    private int y;

    public shape(int x,int y){
        this.x=x;
        this.y=y
    }

    public abstract void onDraw();

    }

    public int getX() {
        return this. x;
    }

    public int getY() {
        return this. y;
    }

or make the attributes protected.

note that x and y will never be set if you create a rect because you are not calling the super constructor

The original example just wont compile... – Gyro Gearless Feb 25 '14 at 14:24 — Gyro Gearless, Feb 25 '14 at 14:24

score 0 · Answer 3 · answered Feb 25 '14 at 14:20

0

You can't. The whole point of it being private is that you can't get at the variable. If the class hasn't given any way of finding it out, you can't get it.

answered Feb 25 '14 at 14:20

Engineer2021

3,288
6
29
51

Access superclass fields

3 Answers3