## Q. Java program to make a simple calculator using switch case.

Here you will find an algorithm and program in Java programming language to make a simple calculator. First let us understand what is calculator?

Explanation : A calculator is used to make mathematical calculations. In this program we will create a simple calculator that can perform an arithmetic operation (+, -, *, /).

## Calculator Program Algorithm

```START
Step 1 : Initialise the two numbers.
Step 2 : Ask the user to enter an option by giving six options.
Step 3 : After getting the option from the user write if conditions for every operation based on the option.
Step 4 : Perform the respective operation.
Step 5 : Print the result.
STOP
```

# Java Program to Make a Simple Calculator

```import java.util.Scanner;
public class LFC {
public static void main(String[] args) {
Scanner reader = new Scanner(System.in);
System.out.print("Enter two operands: ");
// nextDouble() reads the next double from the keyboard
double num1 = reader.nextDouble();
double num2 = reader.nextDouble();
System.out.print("Enter an operator (+, -, *, /):  ");
char ch = reader.next().charAt(0);
double res;
switch(ch)
{
case '+':
res = num1 + num2;
break;
case '-':
res = num1 - num2;
break;
case '*':
res = num1 * num2;
break;
case '/':
res = num1 / num2;
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", num1, ch, num2, res);
}
}
```

#### Output

```Enter an operator (+, -, *, /): *
Enter two operands: 8 6
8.0 * 6.0 = 48.0
```