/* An instance of this class represents an immutable point in two-space
** (i.e., on the cartesian plane).
*/

public class PointIn2Space {

   // instance variables
   // ------------------

   private double x, y;

   // constructor
   // -----------

   /* Establishes this point as having the given x- and y-coordinates.
   */
   public PointIn2Space(double xCoord, double yCoord) {
      x = xCoord;  y = yCoord;
   }

   // observers
   // ---------

   /* Returns the x-coordinate of this point.
   */
   public double getX() { return x; }

   /* Returns the y-coordinate of this point.
   */
   public double getY() { return y; }

   /* Returns the distance between this point and the given one.
   */
   public double distanceTo(PointIn2Space p) {
      return Math.sqrt(squareOf(x - p.getX()) + squareOf(y - p.getY()));
   }

   /* Returns a string describing this point, in the standard notation
   ** (e.g., "(5.2,3.7)").
   */
   public String toString() {
      return "(" + x + "," + y + ")";
   }

   // private (utility)
   // -----------------

   /* Returns the square of the given number.
   */
   private double squareOf(double z) { return z*z; }
}