Calculates the distance to a point, with no parameters ( distance to origin 0,0), two parameters x and y or a variable of the type Point.

PointCalculator.java

public class Point {

    private int x;
    private int y;

    public Point(){
        //empty constructor (no argument constructor)
    }
    public Point(int x, int y){
        this.x = x;
        this.y = y;
    }

    public int getX() {
        return x;
    }

    public void setX(int x) {
        this.x = x;
    }

    public int getY() {
        return y;
    }

    public void setY(int y) {
        this.y = y;
    }
    public double distance(){

        //d(A,B) = sqrt (xB - xA) * (xb - xA) + (yB - yA) * (yB - yA)

        return Math.sqrt((0 - this.x) * (0 - this.x) + (0 - this.y) * (0 - this.y));
    }
    public double distance(int x, int y){
        return Math.sqrt((x - this.x) * (x - this.x) + (y - this.y) * (y - this.y));
    }
    public double distance(Point point){
        int x = point.getX();
        int y = point.getY();

        return Math.sqrt((x - this.x) * (x - this.x) + (y - this.y) * (y - this.y));
    }
}