public class Point
{
    //state or instance variable
    private int x;
    private int y;
    //signature: list of types in the argment list
    public Point(int x, int y)
    {
        this.x = x;
        this.y = y;
    }
    //method name overloading. Two methods can have
    //the same name if their sigs are different.
    public Point()
    {
        this(0,0);
    }
    @Override
    public String toString()
    {
        return String.format("(%s, %s)", x, y);
    }
    @Override
    public boolean equals(Object o)
    {
        //the species test
        if( !(o instanceof Point))
        {
            return false;
        }
        Point that = (Point) o;
        return that.x == x && that.y == y;
    }
    public int getX()
    {
        return x;
    }
    public int getY()
    {
        return y;
    }
    public void setX(int x)
    {
        this.x = x;
    }
    public void setY(int y)
    {
        this.y = y;
    }
    public double distanceTo(Point that)
    {
        return Math.hypot(x - that.x, y - that.y);
    }
    public int taxiCabDistance(Point that)
    {
        return abs(x - that.x) + abs(y - that.y);
    }
    //poopsmith
    private int abs(int x)
    {
        // ternary operator:   P? ifTrue: ifFalse
        // predicate: boolean valued expression.
        // P is one of these
        return x < 0? -x : x;
    }
    public static void main(String[] args)
    {
        Point p = new Point(3,4);
        Point origin = new Point();
        Point q = new  Point(3,4);
        System.out.println(p);
        System.out.println(origin);
        System.out.println(origin.distanceTo(p));
        System.out.println(p.distanceTo(origin));
        System.out.println(origin.taxiCabDistance(p));
        System.out.println(p.taxiCabDistance(origin));
        System.out.println(p == q);
        System.out.println(p.equals(q));

    }
}