Question

/*

Writing a program that displays the following:

calculating area of a circle, calculating area of a rectangle, calculating area of a triangle, and quit.

*/

import java.text.DecimalFormat;

import java.util.Scanner;

public class GeoCalculator

{

  

public static void main(String arg[])

{

char selection;

Scanner get = new Scanner(System.in); //having user input

DecimalFormat twoDigits = new DecimalFormat("0.00"); //formatting area to two decimal places

//display choice of selection

System.out.println("Geometry Calculator");

System.out.println("Please select from the following menu:");

System.out.println("1. Calculate the Area of a Cirlce.");

System.out.println("2. Calculate the Area of a Rectangle.");

System.out.println("3. Calculate the Area of a Triangle.");

System.out.println("4. QUIT");

System.out.print("Please make a selection: ");

selection = get.next().charAt(0);

//checking if selection is between 1 and 4

while (selection < 1 || selection > 4)

{

System.out.println("Try again. Please make a selection (1-4)");

selection = get.next().charAt(0);

}

  

  

//output of selection made

switch (selection)

{

case '1': //getting area of circle

System.out.println("Please enter the circle's radius: ");

double r = get.nextDouble();

double areac = 3.14159 * r * r;

System.out.printf("Area of Circle is: " + twoDigits.format(areac));

break;

case'2': //getting area of rectangle

System.out.printf("Please enter the length: ");

double l = get.nextDouble();

System.out.printf("Please enter the width: ");

double w = get.nextDouble();

  

double arear = l * w;

  

System.out.printf("Area of Rectangle is: " + twoDigits.format(arear));

break;

  

  

case '3': //getting area of triangle

System.out.printf("Please enter the base: ");

double b = get.nextDouble();

System.out.printf("Please enter height: ");

double h = get.nextDouble();

  

double areat = b * h * 0.5;

  

System.out.printf("Area of Triangle is: " + twoDigits.format(areat));

break;

  

  

case '4': //no option

System.out.printf("QUIT");

break;

  

}

}   

  

}

trying to run it and ive been editing back and forth. still no compiling what i need.

Answer 1

Below is your working code: -

/*
Writing a program that displays the following:
calculating area of a circle, calculating area of a rectangle, calculating area of a triangle, and quit.
*/

import java.text.DecimalFormat;
import java.util.Scanner;

public class GeoCalculator {

   public static void main(String arg[]) {
       char selection;
       Scanner get = new Scanner(System.in); // having user input
       DecimalFormat twoDigits = new DecimalFormat("0.00"); // formatting area
                                                               // to two
                                                               // decimal
                                                               // places
       boolean done = false;
       // display choice of selection
       System.out.println("Geometry Calculator");
       System.out.println("Please select from the following menu:");
       System.out.println("1. Calculate the Area of a Cirlce.");
       System.out.println("2. Calculate the Area of a Rectangle.");
       System.out.println("3. Calculate the Area of a Triangle.");
       System.out.println("4. QUIT");
       boolean error = false;

       // checking if selection is between 1 and 4
       while (!done) {
          
           if(!error) {
               System.out.println("Please make a selection: ");
           }
           selection = get.next().charAt(0);
           // output of selection made
           switch (selection) {
           case '1': // getting area of circle
               error = false;
               System.out.println("Please enter the circle's radius: ");
               double r = get.nextDouble();
               double areac = 3.14159 * r * r;
               System.out.printf("Area of Circle is: "
                       + twoDigits.format(areac) + "\n");
               break;
           case '2': // getting area of rectangle
               error = false;
               System.out.printf("Please enter the length: ");
               double l = get.nextDouble();
               System.out.printf("Please enter the width: ");
               double w = get.nextDouble();

               double arear = l * w;

               System.out.printf("Area of Rectangle is: "
                       + twoDigits.format(arear) + "\n");
               break;

           case '3': // getting area of triangle
               error = false;
               System.out.printf("Please enter the base: ");
               double b = get.nextDouble();
               System.out.printf("Please enter height: ");
               double h = get.nextDouble();

               double areat = b * h * 0.5;

               System.out.printf("Area of Triangle is: "
                       + twoDigits.format(areat) + "\n");
               break;

           case '4': // no option
               System.out.printf("QUIT");
               error = false;
               done = true;
               break;
           default:
               error = true;
               System.out.println("Try again. Please make a selection (1-4)");
               break;
           }
       }
   }

}

Output

Geometry Calculator
Please select from the following menu:
1. Calculate the Area of a Cirlce.
2. Calculate the Area of a Rectangle.
3. Calculate the Area of a Triangle.
4. QUIT
Please make a selection:
7
Try again. Please make a selection (1-4)
-2
Try again. Please make a selection (1-4)
1
Please enter the circle's radius:
2
Area of Circle is: 12.57
Please make a selection:
2
Please enter the length: 2
Please enter the width: 5
Area of Rectangle is: 10.00
Please make a selection:
3
Please enter the base: 5
Please enter height: 2
Area of Triangle is: 5.00
Please make a selection:
4
QUIT