Question

Hi, just wanted to see if i understood the question correctly.

(i)

public interface Coordinate {

    public double getDegrees();

    public double getMinutes();

    public double getSeconds();

    public String getDirection();

}

(ii) Could i use an Abstract class instead of the interface and use the Latitude class to extend the Abstract class. (not really sure why this is advantageous? is it because i can pick and choose the methods i want to use, instead of being forced to use the implemented methods )

(iii) public class Latitude implements Coordinate {}

(iv) public class Latitude extends Coordinate{}

Answer 1

-1 and 0 are int not double

'S' is a char not a String

Could i use an Abstract class instead of the interface

Apart from a class and an abstract class you can use incantation which isn’t obvious.

public @interface Coordinate {
    public int getDegrees();
    public int getMinutes();
    public double getSeconds();
    public char getDirection();
}

static class Location implements Coordinate {
    @Override
    public int getDegrees() {
        return 0;
    }

    @Override
    public int getMinutes() {
        return 0;
    }

    @Override
    public double getSeconds() {
        return 0;
    }

    @Override
    public char getDirection() {
        return 0;
    }

    @Override
    public Class<? extends Annotation> annotationType() {
        return Location.class;
    }
}