Question

JAVA program:

Calculate geometric area for 3 shapes(square, rectangle and circle).

1. You need to build a menu that allows users to enter options. Possible options are 'S' for square, 'R' for rectangle and 'C' for circle. HINT: you can use switch statement to switch on string input
   1. Invalid input should throw a message for the user. Example: Invalid input, please try again
2. Each options should ask users for relevant data. HINT: use scanner object to take in length for square, length/width for rectangle and radius for circle
   1. At the class level store a constant variable for PI that cannot be changed. You can use 3.14 for the value
3. Each option should call relevant method that is created at the class level. Methods should take in input received from the users in the step above and return values. HINT: one method for square area calculation, one for rectangle area calculation and one for circle area calculation. Square and rectangle should return int, circle should return double

Expected output:
***Area Calculator***

S  --  Square

R  --  Rectangle

C  --  Circle

S

Please enter length of the square:

2

Area of your square is: 4

***Area Calculator***

S  --  Square

R  --  Rectangle

C  --  Circle

R

Please enter length of the rectangle:

2

Please enter length of the rectangle:

3

Area of your rectangle is: 6

***Area Calculator***

S  --  Square

R  --  Rectangle

C  --  Circle

C

Please enter the redius of the circle:

3

Area of your circle is: 28.26

Answer 1

CODE:

package demo;

import java.util.Scanner;

public class GeometricArea {
  
//   THIS method calculates the area of square
//   this takes side as a parameter
//   returns the area of square
   static int squareArea(int side) {
         
//       calculate the area
       int area = side * side;
      
//       return area
       return area;
   }
     
//   this method calculates the area of rectangle
//   this method takes two parameters length and width
//   return the area of the rectangle
   static int rectangleArea(int length,int width) {
       int area;
//       calculate the area of rectangle
       area = length*width;
//       return the area
       return area;
   }
     
//   this method calculates the area of circle
//   this takes the radius as parameter
//   returns the double value as area
   static double circleArea(int radius) {
//       declare a constant value for PI
       final double PI = 3.14;
         
       double area;
         
//       calculate the area of circle
       area = PI *radius*radius;
         
//       return the area
       return area;
   }
  
//   main function
   public static void main(String[] args) {
      
//       declare the variable for the user choice
       String choice;
      
//       variables for length radius side and width
       int length,width,side,radius;
      
//       create an object for scanner class that takes the input from user
       Scanner in = new Scanner(System.in);
      
//       display the user to choose
       System.out.println("***Area Calculator***");
       System.out.println("S -- Square");
       System.out.println("R -- Rectangle");
       System.out.println("C -- Circle");
      
//       read the user choice
       choice = in.nextLine();
      
//       switch case to switch according to the user
       switch (choice) {
      
//       if the user choice is S then
       case "S":
          
//           read the side of the square from the user
           System.out.println("Please enter length of the square:");
           side = in.nextInt();
          
//           call the method squareArea and pass the side as parameter
           int square_area = squareArea(side);
          
//           print the square_area
           System.out.println("Area of your square is:"+square_area);
          
           break;
          
//       IF THE USER SELECTS R THEN
       case "R":
          
//           ask the user to enter length and width
           System.out.println("Please enter length of the rectangle:");
           length = in.nextInt();
          
           System.out.println("Please enter width of the rectangle:");
           width = in.nextInt();
          
//           call the function rectangleArea and pass the parameters length and width
           int recta_area = rectangleArea(length,width);
          
//           print the area of rectangle
           System.out.println("Area of your rectangle is:"+recta_area);
          
           break;
          
//       if the user selects c then
       case "C":
          
//           ask user to enter the radius of cirlce
           System.out.println("Please enter the redius of the circle:");
          
           radius = in.nextInt();
          
//           call the function circleArea pass parameter radius
           double cricle_area = circleArea(radius);
          
//           print the result of circle area
           System.out.printf("Area of your circle is:%.2f",cricle_area);
          
           break;
//          
//           if the user enters the invalid input the print invalid
       default:
          
           System.out.println("Invalid input, please try again");
           break;
       }
      
      
   }

}