Question

Write a Java program that prompts user to select one of the five shapes(Rectangle, Square, Triangle, Circle, and Parallelogram), then calculate area of the shape,must have input validation and uses more of java library like math class, wrapper class, string methods, use formatted output with the printf method. Finally, create a pseudo-code statement and flowchart

Answer 1

Hi,

Please find the below code which does the exact work described.

I have also added the required comments on the code itself. Please let me know in the comment section if anything else is required.

import java.util.Scanner;
public class HelloWorld{

    public static void main(String []args){
  
    // this is used to take the input from the user
       Scanner scanner = new Scanner(System.in);
        System.out.println("Please enter the shape to calculate area (1-5):\n" +
        "1.Rectangle\n" +
        "2.Square\n" +
        "3.Triangle\n" +
        "4.Circle\n" +
        "5.Parellelogram");

        // validating the required input
        // this prompts the user to enter the input untill the valid input has been given
        while(!scanner.hasNextLine()) {
            System.out.println("Please enter the required input");
            scanner.next();
        }
        String shape = scanner.nextLine(); // Read user input

        /* below we will have a switch case to switch between the implemented methods to call
        * We have to also pass the scanner object which will be shared by each implemented methods
        */
        switch(shape) {
            case "1":
                rectangle(scanner);
                break;
            case "2":
                square(scanner);
                break;
            case "3":
                triangle(scanner);
                break;
            case "4":
                circle(scanner);
                break;
            case "5":
                parelleogram(scanner);
                break;
            default:
                System.out.println("Please enter the values from 1 to 5 only");
                break;
        }
    }
   
    static void rectangle(Scanner scanner) {
      System.out.println("Enter the length of Rectangle:");

      while(!scanner.hasNextDouble()) {
          System.out.println("Please enter the required input");
          scanner.next();
      }
        double length = scanner.nextDouble();
        System.out.println("Enter the width of Rectangle:");
        while(!scanner.hasNextDouble()) {
            System.out.println("Please enter the required input");
            scanner.next();
      }
        double width = scanner.nextDouble();
      
        //Area = length * length
        double area = length*width;
      System.out.println("Area of the rectangle is :" + area);
    }

    static void square(Scanner scanner) {
        System.out.println("Enter Side of Square:");
        while(!scanner.hasNextDouble()) {
            System.out.println("Please enter the required input");
            scanner.next();
        }
        double side = scanner.nextDouble();
      
        //Area = side*side
        double area = side*side;
        System.out.println("Area of Square is: " + area);
    }
    static void triangle(Scanner scanner) {
        System.out.println("Enter the width of the Triangle:");
        while(!scanner.hasNextDouble()) {
            System.out.println("Please enter the required input");
            scanner.next();
        }
        double base = scanner.nextDouble();

        System.out.println("Enter the height of the Triangle:");
        while(!scanner.hasNextDouble()) {
            System.out.println("Please enter the required input");
            scanner.next();
        }
        double height = scanner.nextDouble();

        //Area = (width*height)/2
        double area = (base* height)/2;
        System.out.println("Area of Triangle is: " + area);
    }

    static void circle(Scanner scanner) {
        System.out.print("Enter the radius: ");
        while(!scanner.hasNextDouble()) {
            System.out.println("Please enter the required input");
            scanner.next();
        }
        double radius = scanner.nextDouble();
      
        //Area = PI*radius*radius
        double area = Math.PI * (radius * radius);
        System.out.println("The area of circle is: " + area);
    }

    static void parelleogram(Scanner scanner) {
        System.out.println("Enter the height:");
        while(!scanner.hasNextDouble()) {
            System.out.println("Please enter the required input");
            scanner.next();
        }
        double d1= scanner.nextDouble();
        System.out.println("Enter the breadth:");
        while(!scanner.hasNextDouble()) {
            System.out.println("Please enter the required input");
            scanner.next();
        }
        double d2= scanner.nextDouble();
       
        //Area = (height*breadth)
        double area=(d1*d2) ;
        System.out.println("Area of Parallelogram is: " + area);
    }
}

Flow chart for the above code: