Java Program to Make a Calculator using Switch Case

In this Program we are making a simple calculator that performs addition, subtraction, multiplication and division based on the user input. The program takes the value of both the numbers (entered by user) and then user is asked to enter the operation (+, -, * and /), based on the input program performs the selected operation on the entered numbers using switch case.

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Example: Program to make a calculator using switch case in Java

import java.util.Scanner;

public class JavaExample {

    public static void main(String[] args) {

    	double num1, num2;
        Scanner scanner = new Scanner(System.in);
        System.out.print("Enter first number:");

        /* We are using data type double so that user
         * can enter integer as well as floating point
         * value
         */
        num1 = scanner.nextDouble();
        System.out.print("Enter second number:");
        num2 = scanner.nextDouble();

        System.out.print("Enter an operator (+, -, *, /): ");
        char operator = scanner.next().charAt(0);

        scanner.close();
        double output;

        switch(operator)
        {
            case '+':
            	output = num1 + num2;
                break;

            case '-':
            	output = num1 - num2;
                break;

            case '*':
            	output = num1 * num2;
                break;

            case '/':
            	output = num1 / num2;
                break;

            /* If user enters any other operator or char apart from
             * +, -, * and /, then display an error message to user
             * 
             */
            default:
                System.out.printf("You have entered wrong operator");
                return;
        }

        System.out.println(num1+" "+operator+" "+num2+": "+output);
    }
}

Output:

Enter first number:40
Enter second number:4
Enter an operator (+, -, *, /): /
40.0 / 4.0: 10.0