condition compares using double, then return int

Week 6: Methods of OO Programming/08. Comparable Point

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+In the program, the class 'Point', which you are familiar from the beginning of the tutorial, is defined.
+
+Implement a 'comparison method' for the class:
+public int compareTo(Point anotherPoint)
+
+The comparison value of two points is based on the distance of the points from the origin - the greater the distance, the "larger" the point.
+Note that the class already has a necessary method for calculating the distance.
+
+
+
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.Random;
+
+public class Test{
+    public static void main(String[] args){
+        final Random r = new Random();
+        
+        
+        ArrayList<Point> points = new ArrayList<>();
+        
+        points.add(new Point(-4,-3));
+        points.add(new Point(1,2));
+        points.add(new Point(6,-3));
+        points.add(new Point(-1,0));
+        points.add(new Point(-14,1));
+        points.add(new Point(1,11));
+        points.add(new Point(-5,-5));
+        points.add(new Point(-1,8));
+        
+        System.out.println("Points before:");
+        points.stream().forEach(pt -> System.out.println("" + pt));
+        
+        Collections.sort(points);
+        System.out.println("Points sorted:");
+        points.stream().forEach(pt -> System.out.println(pt));
+
+    }
+}
+
+
+
+
+
+class Point implements Comparable<Point>{
+    private int x;
+    private int y;
+    
+    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;
+    }
+
+
+    //////////////////////////////////////////////
+    // object method calls class method
+    //////////////////////////////////////////////
+    public double getDistance() {
+        return Point.distanceFromOrigin(this);
+    }
+    
+    public static double distanceFromOrigin(Point point) {
+        return Math.sqrt(point.getX() * point.getX() + 
+                point.getY() * point.getY());
+    }
+    
+    @Override
+    public String toString() {
+        return "(" + x + "," + y + ") - distance: " + getDistance();
+    }
+    //////////////////////////////////////////////
+
+
+
+
+
+    //ADD
+    public int compareTo(Point anotherPoint) {
+        double thisDistance = this.getDistance();
+        double otherDistance = anotherPoint.getDistance();
+    
+        if (thisDistance < otherDistance) {
+            return -1;
+        } 
+        else if (thisDistance > otherDistance) {
+            return 1;
+        } 
+        else {
+            return 0;
+        }
+    }
+
+    
+
+}
+
+
+
+
+
+
+Points before:
+(-4,-3) - distance: 5.0
+(1,2) - distance: 2.23606797749979
+(6,-3) - distance: 6.708203932499369
+(-1,0) - distance: 1.0
+(-14,1) - distance: 14.035668847618199
+(1,11) - distance: 11.045361017187261
+(-5,-5) - distance: 7.0710678118654755
+(-1,8) - distance: 8.06225774829855
+
+Points sorted:
+(-1,0) - distance: 1.0
+(1,2) - distance: 2.23606797749979
+(-4,-3) - distance: 5.0
+(6,-3) - distance: 6.708203932499369
+(-5,-5) - distance: 7.0710678118654755
+(-1,8) - distance: 8.06225774829855
+(1,11) - distance: 11.045361017187261
+(-14,1) - distance: 14.035668847618199
+