Universidad Carlos III de Madrid

1. Program a constructor for the Point class. It must receive both point coordinates as input parameters.

1. Program the toString() method so that it returns a string with the representation of the point according to the following format:

   (x, y)

   where x and y must be replaced by their respectives values. The prototype of the method is specified as follows:

   public String toString() {
       /* ... */
   }

   Hint

   Remember that the "+" operator, applied to strings of characters, allows to concatenate them. But if you try to concatenate a number with a string, don't worry, Java converts automaticaly the number to a string to make the "addition".

1. Program a class called TestingPoint which has a main method. This method must receive, as command line arguments, the x and y coordinates, then create a new Point object with those coordinates and print a text representation of such object to the standard output (the console).

   The program must check that the number of command line arguments received is correct.

   Hint

   The parseDouble() method of the Double class (click to follow the link to the API Javadoc) transforms a string of characters to a double primitive type.

1. Program the following access methods that return the coordintate values x and y in the Point class. The prototype of those methods is shown below:

   public double getX() {
       /* ... */
   }
   
   public double getY() {
       /* ... */
   }

2. Modify the code of your TestingPoint class to check that its behaviour is correct.

1. Program a method of the Point class that returns the distance from the point to the origin of the coordinates. The prototype of the method is as follows:

   public double distanceToOrigin() {
   /*  complete */
   }

   Modify the code of your TestingPoint class to check that its behaviour is correct.

2. Program a method of the Point class that returns the distance between the point represented by the actual object instance and another instance of Point that is received as input parameter. The prototype of the method is as follows:

   public double distance(Point anotherPoint) {
       /* completar */
   }

   Modify the code of your TestingPoint class to check that its behaviour is correct.

1. Program a method of the Point class that returns the quadrant in which the point is located. The prototype of the method is as follows:

   • It returns 0 if it is placed at the origin of coordinates or on any of the axis.

   • It returns 1 if it is placed at the first quadrant (both x and y positives).

   • It returns 2 if it is placed at the second quadrant (x negative and y positive).

   • It returns 3 if it is placed at the third quadrant (both x and y negatives).

   • It returns 4 if it is placed at the fourth quadrant (x positive and y negative).

   The prototype of the method is shown below:

   public int quadrant()  {
     /* complete */
   }

   Modify the code of your TestingPoint class to check that its behaviour is correct.

1. Program a method of the Point class that receives, as input parameter, an array of Point objects and returns a reference to the object of the array that represents the nearest point to the current object (this). The prototype of the method is as follows:

   public Point nearest(Point[] otherPoints) {
     /* complete */
   }

   Modify the code of your TestingPoint class to check that its behaviour is correct.

1. Program the Triangle class with its attributes and a constrctor that receives three points (vertexes) as input parameters.

Program a class to test it.

1. Program the edgesLength() method of the Triangle class. It must return an array of three decimals (double) that represents, respectively, the length of each side of the triangle. The prototype of the method is as follows:

   public double[] edgesLength() {
       /* complete... */
   }