Calculator

ve the knowledge of the following Java programming topics:

Java switch Statement

Java Scanner Class

Example: Simple Calculator using switch Statement

import java.util.Scanner;

public class Calculator {

    public static void main(String[] args) {

        Scanner reader = new Scanner(System.in);

        System.out.print("Enter two numbers: ");

        // nextDouble() reads the next double from the keyboard

        double first = reader.nextDouble();

        double second = reader.nextDouble();

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

        char operator = reader.next().charAt(0);

        double result;

        switch(operator)

        {

            case '+':

                result = first + second;

                break;

            case '-':

                result = first - second;

                break;

            case '*':

                result = first * second;

                break;

            case '/':

                result = first / second;

                break;

            // operator doesn't match any case constant (+, -, *, /)

            default:

                System.out.printf("Error! operator is not correct");

                return;

        }

        System.out.printf("%.1f %c %.1f = %.1f", first, operator, second, result);

    }

}