# Java Code Example: simple calculator

The simple calculator expects user input for the arithmetic operation, and for the two numbers that are to be calculated together. Depending on the arithmetic symbol, a switch statement is used to decide which arithmetic operation is to be performed.

``````import java.util.Scanner;

public class SimpleCalculator {
public static void main(String[] args) {
Scanner scan = new Scanner(System.in);
double firstNumber, secondNumber, result = 0.0;
char arithmeticOperation;

System.out.print("Please enter an arithmetic operation (+, -, *, /): ");
arithmeticOperation = scan.next().charAt(0);
firstNumber = scan.nextInt();
secondNumber = scan.nextInt();

switch (arithmeticOperation) {
case '+' :
result = firstNumber + secondNumber;
break;
case '-' :
result = firstNumber - secondNumber;
break;
case '*' :
result = firstNumber * secondNumber;
break;
case '/' :
result = firstNumber / secondNumber;
break;
default:
System.out.print("Unknown arithmetic symbol");
}

System.out.print(firstNumber + " " + arithmeticOperation + " " + secondNumber + " = " + result);
}
}``````
##### Output
``````Please enter an arithmetic operation (+, -, *, /): -
34.0 - 23.0 = 11.0``````
##### Code Explanation

Here’s a detailed explanation of the code:

1. We import the `Scanner` class to read input from the user.
``import java.util.Scanner;``
1. We define the `SimpleCalculator` class with a `main` method.
``````public class SimpleCalculator {
public static void main(String[] args) {``````
1. We create a new `Scanner` object to read input from the user.
``Scanner scan = new Scanner(System.in);``
1. We declare three `double` variables to hold the first number, second number, and result of the calculation.
``double firstNumber, secondNumber, result = 0.0;``
1. We declare a `char` variable to hold the arithmetic operation entered by the user.
``char arithmeticOperation;``
1. We prompt the user to enter an arithmetic operation and read it using the `Scanner` object.
``````System.out.print("Please enter an arithmetic operation (+, -, *, /): ");
arithmeticOperation = scan.next().charAt(0);``````
1. We prompt the user to enter the first number and read it using the `Scanner` object.
``````System.out.print("Please enter your first number: ");
firstNumber = scan.nextInt();``````
1. We prompt the user to enter the second number and read it using the `Scanner` object.
``````System.out.print("Please enter your second number: ");
secondNumber = scan.nextInt();``````
1. We use a `switch` statement to determine which arithmetic operation was selected and perform the appropriate calculation.
`````` switch (arithmeticOperation) {
case '+' :
result = firstNumber + secondNumber;
break;
case '-' :
result = firstNumber - secondNumber;
break;
case '*' :
result = firstNumber * secondNumber;
break;
case '/' :
result = firstNumber / secondNumber;
break;
default:
System.out.print("Unknown arithmetic symbol");
}``````
1. We display the result of the calculation using `System.out.print`.
``System.out.print(firstNumber + " " + arithmeticOperation + " " + secondNumber + " = " + result);``