Question

IN JAVA: Write a program that displays a menu as shown in the sample run. You can enter 1, 2, 3, or 4 for choosing an addition, subtraction, multiplication, or division test. After a test is finished, the menu is redisplayed. You may choose another test or enter 5 to exit the system. Each test generates two random single-digit numbers to form a question for addition, subtraction, multiplication, or division. For a subtraction such as number1 – number2, number1 is greater than or equal to number2. For a division question such as number1 / number2, number2 is not zero. I have enclose the program below and also in D2L, what you are required to do is to include exception handler that deals with nonnumeric operands, ArithemeticException and any others you think is required by this program. Make sure the program can recover from an outofboundsexeption, so it resets the menu. Also, make the division show the decimal answer, and not just the whole number.

Use this program as the foundation:

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

public class MathTutor {
   public static void main(String[] args) {
       Scanner input = new Scanner(System.in);

       System.out.println("Main menu");
       System.out.println("1: Addition");
       System.out.println("2: Subtraction");
       System.out.println("3: Multiplication");
       System.out.println("4: Division");
       System.out.println("5: Exit");
       int userChoice = 0;
       System.out.println("Enter a choice:");
       userChoice = input.nextInt();
       //WORK ON WHILE
       while (userChoice != 5) {

           int firstNum = (int)(Math.random() * 10);
           int secondNum = (int)(Math.random() * 10);

           switch (userChoice) {
           case 1:
               int adding = firstNum + secondNum;
               System.out.println(firstNum +" + "+secondNum+"?");
               int addingInput = input.nextInt();
               if (addingInput == adding)
                   System.out.println("correct");
               else
                   System.out.println("Your answer is wrong. The correct answer is "+ adding);
               break;

           case 2:
               int sub = firstNum - secondNum;
               System.out.println(firstNum +" - "+secondNum+"?");
               int subInput = input.nextInt();
               if (subInput == sub)
                   System.out.println("correct");
               else
                   System.out.println("Your answer is wrong. The correct answer is "+ sub);
               break;

           case 3:
               int mult = firstNum * secondNum;
               System.out.println(firstNum +" * "+secondNum+"?");
               int multInput = input.nextInt();
               if (multInput == mult)
                   System.out.println("correct");
               else
                   System.out.println("Your answer is wrong. The correct answer is "+ mult);
               break;

           case 4:
               while (secondNum == 0){
                   // to make sure the bottom number is never zero
                   secondNum = (int)Math.round((Math.random()*10));
               };
               double div = firstNum / secondNum;
               System.out.println(firstNum +" / "+secondNum+"?");
               double divInput = input.nextDouble();

               if (divInput == div)
                   System.out.println("correct");
               else
                   System.out.println("Your answer is wrong. The correct answer is "+ div);
               break;

           case 5:
               System.exit(0); break;

           default:
               System.out.println("Error: Out of range");
               System.exit(0);
           }
           System.out.println("Enter a choice:");
           userChoice = input.nextInt();
       }

       System.out.println("Thank you for using the Math Program. Have a Great Day!");

   }
}

Answer 1

import java.util.*;
import java.lang.Math;
public class Main
{
   public static void main(String[] args) {
   Scanner input = new Scanner(System.in);
   //Random rand = new Random();
System.out.println("Main menu");
System.out.println("1: Addition");
System.out.println("2: Subtraction");
System.out.println("3: Multiplication");
System.out.println("4: Division");
System.out.println("5: Exit");
int choice=0;
System.out.println("Enter a choice:");
try{//use this try block for checking input mismatch
choice = input.nextInt();
while(choice!=5)
{
int firstNum=(int)(Math.random()*10);
int secondNum=(int)(Math.random()*10);
try{
switch(choice)
{
case 1:
int adding = firstNum + secondNum;
System.out.println(firstNum +" + "+secondNum+"?");
int addingInput = input.nextInt();
if (addingInput == adding)
System.out.println("correct");
else
System.out.println("Your answer is wrong. The correct answer is "+ adding);
break;
case 2:
while(firstNum<secondNum)//read the values until we get firstnum>secondNum
{
firstNum=(int)(Math.random()*10);
secondNum=(int)(Math.random()*10);
}
int sub = firstNum - secondNum;
System.out.println(firstNum +" - "+secondNum+"?");
int subInput = input.nextInt();
if (subInput == sub)
System.out.println("correct");
else
System.out.println("Your answer is wrong. The correct answer is "+ sub);
break;
case 3:
int mult = firstNum * secondNum;
System.out.println(firstNum +" * "+secondNum+"?");
int multInput = input.nextInt();
if (multInput == mult)
System.out.println("correct");
else
System.out.println("Your answer is wrong. The correct answer is "+ mult);
break;
case 4:
while (secondNum == 0){
// to make sure the bottom number is never zero
secondNum = (int)Math.round((Math.random()*10));
}
double div = (double)firstNum / secondNum;//use typecasting here to get decimal result
System.out.println(firstNum +" / "+secondNum+"?");
double divInput = input.nextDouble();
if (divInput == div)
System.out.println("correct");
else
System.out.println("Your answer is wrong. The correct answer is "+ div);
break;
case 5:
System.exit(0); break;

default:
System.out.println("Error: Out of range");
System.exit(0);
  
}
}
catch(ArithmeticException e)//we used exception this is for arithmetic exception
{
System.out.println("We got arithmetic exception");
}
catch(IndexOutOfBoundsException e)//this is for indexout of bounds exception
{
//they will check one by one it will print when any catch statement satisfies this
System.out.println("Out of bounds exception");
}
catch(NumberFormatException e)
{
System.out.println("number format exception");
}
catch(Exception e)//general exception
{
//if above nothing cathes it defaully catches
System.out.println("Exception is "+e);
}
System.out.println("Main menu");
System.out.println("1: Addition\n2: Subtraction\n3: Multiplication\n4: Division\n5: Exit");
System.out.println("Enter a choice:");
choice = input.nextInt();
}
}
catch(InputMismatchException e)
{
System.out.println("Input mismatch Enter numeric input");
}
   }
}