Question

Hi. This is a prototype of Java.

The following Java program was developed for prototyping a mini calculator. Run the program and provide your feedback as the user/project sponsor. (Save the code as MiniCalculator.java; compile the file: javac MiniCalculator.java; and then run the program: java MiniCalculator).

HINTs: May give feedback to the data type and operations handled by the program, the way the program to get numbers and operators, the way the calculation results are output, the termination of the program and the way the program handles wrong data types and other exceptions.

import java.util.Scanner;

class DataAndOperator {

int operand1;

int operand2;

int result;

String operator;

}

public class MiniCalculator {

public static void main(String[] args) {

    // Scan for keyboard input.

    Scanner input = new Scanner(System.in);

    // operands and operator

    DataAndOperator dataAndOperator = new DataAndOperator();

    // Loop until the user enters zeros for both numbers.

    do {

         System.out.println("(Enter zeros for both operands to exit)");

         GetOperands(input, dataAndOperator);

         if ((dataAndOperator.operand1 != 0) || (dataAndOperator.operand2 != 0))

         {

           System.out.print("Enter the operator(+, -, *, / or %): ");

           dataAndOperator.operator = input.next();

// Print the result of the calculations.

if (DoMath(dataAndOperator)) {

    System.out.println(dataAndOperator.operand1 + " "

    + dataAndOperator.operator.charAt(0) + " "

    + dataAndOperator.operand2 + " = " + dataAndOperator.result);

} else

          System.out.println("Calculation not performed!");

}while ((dataAndOperator.operand1 != 0) || (dataAndOperator.operand2 != 0));

}

System.out.println("Exiting...");

}

private static void GetOperands(Scanner _input, DataAndOperator _dataAndOperator) {

while (true) { //until get the right data type input System.out.print("Enter first number: ");
try {

             _dataAndOperator.operand1 = _input.nextInt();

break; }

       catch (Exception e) {

             _input.nextLine();

             System.out.println("Wrong data typ. Please enter an integer.");

} }

while (true) { //until get the right data type input System.out.print("Enter second number: ");
try {

             _dataAndOperator.operand2 = _input.nextInt();

break; }

       catch (Exception e) {

             _input.nextLine();

} }

}

System.out.println("Wrong data typ. Please enter an integer.");

// Switch statement to decide what operation to do based on the operand.

private static boolean DoMath (DataAndOperator _dataAndOperator) {

       boolean success=true;

       char _operator=_dataAndOperator.operator.charAt(0);

       switch (_operator) {

       case '+':

             _dataAndOperator.result= _dataAndOperator.operand1 +

             _dataAndOperator.operand2;

             break;

       case '-':

             _dataAndOperator.result= _dataAndOperator.operand1 -

             _dataAndOperator.operand2;

             break;

       case '*':

             _dataAndOperator.result= _dataAndOperator.operand1 *

             _dataAndOperator.operand2;

             break;

       case '/':

             try {

_dataAndOperator.result= _dataAndOperator.operand1 /

_dataAndOperator.operand2;

}

catch (Exception e) {

success=false;

System.out.println("Cannot be divided by 0.");

}

       break;

case '%':

try {

       _dataAndOperator.result= _dataAndOperator.operand1 %

       _dataAndOperator.operand2;

}

catch (Exception e) {

success=false;

System.out.println("Cannot be modulared by 0.");

}

       break;

default:

System.out.println("Please select one operator from { +, -, *, /, % }.");

       success=false;

}

return success;

} }

Answer 1

Please find the answer below.
Please do comments in case of any issue. Also, don't forget to rate the question. Thank You.

Given code will provide the result back after applying the following operators

+, -, *, / or %.

operand will be integers.

a sample execution is as below:

(Enter zeros for both operands to exit) 1 2 Enter the operator (+, -, *, / or %): + 1 + 2 = 3

on proving operands other than integer it will show error and prompt the user to enter numbers again.

(Enter zeros for both operands to exit) 11.11 Wrong data typ. Please enter an integer.

On entering the wrong operator it will show error and asks the user to enter operand again.

(Enter zeros for both operands to exit) 21 3 Enter the operator (+,-, *, / or %): f Please select one operator from { +, -, *, I, %}. Calculation not performed!

Arithmetic exceptions also handled such as divide b zero

(Enter zeros for both operands to exit) 3 10 Enter the operator (+,-, *, , or $): / Cannot be divided by 0.

The program ends when both operands are zero

(Enter zeros for both operands to exit) 00 00 Exiting...