Question

JAVA: Create a circle that contains the following... Sample code to work from provided below.

FIELDS:

• a private double that holds the radius.

CONSTRUCTORS

• a no argument constructor that sets the radius to zero
• a constructor that takes a single argument of type double which is the radius.

METHODS

• a method called "getRadius" which returns the current radius
• a method called "setRadius" which takes a single parameter of type double containing the new radius
• a method called "getArea" which returns the area of the circle (area = pi times radius squared)
• a method called "getPerimeter" which returns the perimeter of the circle (perimeter = 2*pi*r)
• a method called "toString" which returns the information about the radius as shown below
• a method called "equals" which takes a Circle as an argument and returns a boolean indicating if the two Circles are equivalent (in this case that just means they have the same radius.

Sample Code to work from: (Driver class & Test class)

public class Circle {
private double radius;
  
/**
* No argument constructor. Creates a Circle with radius 0
* */
// Your code here
  
/**
* Constructor, creates a circle with the provided radius
* @param radius - the desired radius of our circle
* */
// Your code here
  
/**
* Set new radius for this circle
* @param radius - the new radius for our circle
* */
// Your code here
  
/**
* Get the current radius of our circle
* @return the radius of this circle as a double
*/
// Your code here
  
/**
* Get the area of our circle as calculated by PI*r*r
* @return the area of the circle
*/
// Your code here
  
/**
* Get's the perimeter of the circle as 2 * PI * r
* @return the perimeter as a double
*/
// Your code here
  
/**
* Builds a string containing the information about the circle
* @return String containing the info about the circle
*/
  
/* Your output should look like this:
This is a circle
Radius: 10.00
Area: 314.16
Perimeter: 62.83
*/
//@Override
// Your code here
  
/*
* Tests a circle passed in as an argument for equality with
* current circle
* @param Circle c - The Circle to compare to the current circle
*/
  
//public boolean equals(Circle c){
// Your code here
//}
}

class CircleTest{
public static void main(String[] args){
/* Uncomment after you complete the no argument constructor
System.out.println("Creating circle1");
Circle circle1 = new Circle();
*/
  
/* Uncomment after you complete the single argument constructor
System.out.println("Creating circle2");
Circle circle2 = new Circle(1.0);
System.out.println("Creating circle2");
Circle circle3 = new Circle(10.0);
  
*/
  
System.out.println("\n\nTesting methods\n");
/* Uncomment after you write your getters
System.out.println("Testing Getters");
System.out.println("circle1 radius: " + circle1.getRadius());
System.out.println("circle1 area: " + circle1.getArea());
System.out.println("circle1 perimeter: " + circle1.getPerimeter());
*/
  
/*Uncomment after you get setters written
System.out.println("\n\nTesting Setters");
System.out.print("Set circle2 radius to 10: ");
circle2.setRadius(10.0);
if (circle2.getRadius() <= 10.0001 && circle2.getRadius() >= 9.9999){
System.out.println("Success");
} else {
System.out.println("Failed");   
}
*/

/* Uncomment when you complete your toString() method
System.out.println("\n\nTesting toString() method:");
System.out.println(circle2);
*/
  
  
/* Uncomment after you write your .equals() method
System.out.println();
System.out.print("\n\nTesting equals() method: circle1.equals(circle2) (should return false):");
System.out.println(circle1.equals(circle2));
System.out.print("Testing equals() method: circle2.equals(circle3) (should return true):");
System.out.println(circle2.equals(circle3));
*/
}
}

Answer 1

Note: Could you plz go through this code and let me know if u need any changes in this.Thank You
=================================

// Circle.java

public class Circle {
   private double radius;

   /**
   * No argument constructor. Creates a Circle with radius 0
   * */
   // Your code here
public Circle() {
   this.radius=0;
   }
   /**
   * Constructor, creates a circle with the provided radius
   *
   * @param radius
   * - the desired radius of our circle
   **/

   /**
   * @param radius
   */
   public Circle(double radius) {
       this.radius = radius;
   }

   /**
   * Set new radius for this circle
   *
   * @param radius
   * - the new radius for our circle
   **/
public void setRadius(double radius) {
       this.radius = radius;
   }

   /**
   * Get the current radius of our circle
   *
   * @return the radius of this circle as a double
   */
   public double getRadius()
   {
       return radius;
   }

   /**
   * Get the area of our circle as calculated by PI*r*r
   *
   * @return the area of the circle
   */
   public double getArea()
   {
       return Math.PI*radius*radius;
   }

   /**
   * Get's the perimeter of the circle as 2 * PI * r
   *
   * @return the perimeter as a double
   */
   public double getPerimeter()
   {
       return 2*Math.PI*radius;
   }

   /**
   * Builds a string containing the information about the circle
   *
   * @return String containing the info about the circle
   */

     
   /*
   * Your output should look like this: This is a circle Radius: 10.00 Area:
   * 314.16 Perimeter: 62.83
   */
   // @Override
   // Your code here

   @Override
       public String toString() {
       String s=new String().format("This is a circle Radius: %.2f Area: %.2f Perimeter: %.2f\n",radius, getArea(),getPerimeter());
           return s;
       }
  
     
   /*
   * Tests a circle passed in as an argument for equality with current circle
   *
   * @param Circle c - The Circle to compare to the current circle
   */

public boolean equals(Circle c){
   if(this.radius == c.getRadius())
       return true;
   else
       return false;
   }

  
}

==============================================

// CircleTest.java

public class CircleTest {
   public static void main(String[] args) {
       /*
       * Uncomment after you complete the no argument constructor
       */
       System.out.println("Creating circle1");
       Circle circle1 = new Circle();
         

       /*
       * Uncomment after you complete the single argument constructor
       */
       System.out.println("Creating circle2");
       Circle circle2 = new Circle(1.0);
       System.out.println("Creating circle2");
       Circle circle3 =new Circle(10.0);
      

       System.out.println("\n\nTesting methods\n");
       /*
       * Uncomment after you write your getters
       */
       System.out.println("Testing Getters");
       System.out.println("circle1 radius: " + circle1.getRadius());
       System.out.println("circle1 area: " + circle1.getArea());
       System.out.println("circle1 perimeter: " + circle1.getPerimeter());
         
       /*
       * Uncomment after you get setters written
       */
       System.out.println("\n\nTesting Setters");
       System.out.print("Set circle2 radius to 10: ");
       circle2.setRadius(10.0);
       if (circle2.getRadius() <= 10.0001 && circle2.getRadius() >= 9.9999)
       {
           System.out.println("Success");
       }
       else
       {
           System.out.println("Failed");
       }
         

       /*
       * Uncomment when you complete your toString() method
       */
       System.out.println("\n\nTesting toString() method:");
       System.out.println(circle2);
         

       System.out.println();
       System.out.print("\n\nTesting equals() method: circle1.equals(circle2) (should return false):");
       System.out.println(circle1.equals(circle2));
       System.out.print("Testing equals() method: circle2.equals(circle3) (should return true):");
       System.out.println(circle2.equals(circle3));
   }
}

==============================================

Output:

=====================Could you plz rate me well.Thank You