Question

Add a new method to the Point class and change the attributes (x, y) to private from the above question: public double distance(Point next) This method returns the distance between the current Point object and the next Point object in the parameter. The distance between two points is the square root of the sum of the square of the differences of the x and y coordinates: square root of ( (x2 – x1)2 + (y2 – y1)2 ). (6 points) In the Point class, add private to int x and int y. You will have to modify the RefereceX.java and Point.java to deal with this change of modifier from the public to private. (6 points) Based the question 4 codes with the above additions, you should have the following results ( 3 points to display results) inside addTox(..): 14 14 7 9 14 3 inside addTox(..): 18 18 7 9 14 18 distance of p1 from origin is 14.142135623730951 distance of p2 from origin is 18.439088914585774 distance between p1 and p2 is = 4.47213595499958 Code: public class Point { int x; int y; // Constructs a new point with the given (x, y) location. // pre: initialX >= 0 && initialY >= 0 public Point(int initialX, int initialY) { this.x = initialX; this.y = initialY; } // Returns the distance between this point and (0, 0). public double distanceFromOrigin() { return Math.sqrt(x * x + y * y); } // Shifts this point's location by the given amount. // pre: x + dx >= 0 && y + dy >= 0 public void translate(int dx, int dy) { this.x += dx; this.y += dy; } public double distance(Point next) { //help } } public class ReferenceX { public static void main(String[] args) { int x = 7; int y = 9; Point p1 = new Point(1, 2); Point p2 = new Point(3, 4); addToX(x, p1); System.out.println(x + " " + y + " " + p1.x + " " + p2.x); addToX(y, p2); System.out.println(x + " " + y + " " + p1.x + " " + p2.x); } public static void addToX(int x, Point p1) { x += x; p1.x = x; System.out.println(" inside addTox(..): " + x + " " + p1.x); } }

Answer 1

Answer:

Following are the code to this question:

   public double distance(Point next) //defining distance method that accepts Constructor

   {

   int x1,x2,y1,y2;//defining integer variables

   double d;//defining double variable dis

   x1=this.x; //use x1 variable that use this keyword to store x variable value

   y1=this.y;//use y1 variable that use this keyword to store y variable value

   x2=next.x;//use x2 variable that use this keyword to store x variable value

   y2=next.y;//use y1 variable that use this keyword to store y variable value

   d=Math.sqrt((x1-0)*(x1-0) + (y1-0)*(y1-0));//use d variable that calculates distance between p1 to origin and store its value

   d=Math.sqrt((x2-0)*(x2-0) + (y2-0)*(y2-0));//use d variable that calculates distance between p2 to origin and store its value

   d=Math.sqrt((x2-x1)*(x2-x1) + (y2-y1)*(y2-y1));//calculating the distance from p1 to p2 and store its value

   return d;//return dis value

   }

Explanation:

In the above-given code, the double type method "distance" is defined, that accepts a constructor in its parameter, and inside the method, four integer variable "x1,x2,y1, and y2" and one double variable "d" is declared.  

After holding the value of x and y into the declared integer variable the "d" variable is used, that uses the maths square method with an integer variable, which holds p1 to origin value, p2 to origin value, and the distance from p1 to p2, and use the return keyword for return its value.