# Calculator using switch case in JavaScript | Complete code

Simply take input “add”, “divide”, “multiply”, or “subtract” option form use along with 2 numbers then Calculator using switch case in JavaScript.

In this tutorial, you’ll learn how to build a calculator program in JavaScript using a switch case statement. This example demonstrates how to create a basic calculator that can perform addition, subtraction, multiplication, and division operations on two numbers based on the user’s input.

## Calculator using switch case in JavaScript

Simple example code user is prompted to enter an operator (either +, , *, or /) and two numbers.

``````<!DOCTYPE html>
<html>
<body>

<script>

let result;

const operator = prompt('Enter operator ( either +, -, * or / ): ');

const number1 = parseFloat(prompt('Enter first number: '));
const number2 = parseFloat(prompt('Enter second number: '));

switch(operator) {
case '+':
result = number1 + number2;
console.log(`\${number1} + \${number2} = \${result}`);
break;

case '-':
result = number1 - number2;
console.log(`\${number1} - \${number2} = \${result}`);
break;

case '*':
result = number1 * number2;
console.log(`\${number1} * \${number2} = \${result}`);
break;

case '/':
result = number1 / number2;
console.log(`\${number1} / \${number2} = \${result}`);
break;

default:
console.log('Invalid operator');
break;
}
</script>

</body>
</html
>``````

Output:

You can simply add a button to call a function like this

``````<script>
function Calculatrice(a, b, op) {

switch (op) {

case '+':
return a + b
break;
case '-':
return a - b
break;
case '*':
return a * b
break;
case '/':
return a / b
break;

}
}
console.log(Calculatrice(5, 5, '+'));

</script>``````

Output: 10

OR

``````function calculator(operator, num1, num2) {
switch(operator) {
case '+':
return num1 + num2;
case '-':
return num1 - num2;
case '*':
return num1 * num2;
case '/':
return num1 / num2;
default:
return 'Invalid operator';
}
}

// Example usage:
console.log(calculator('+', 2, 3)); // Output: 5
console.log(calculator('-', 5, 2)); // Output: 3
console.log(calculator('*', 4, 6)); // Output: 24
console.log(calculator('/', 10, 2)); // Output: 5
console.log(calculator('%', 10, 3)); // Output: 'Invalid operator'``````

In this example, we have a `calculator` function that takes three parameters: `operator`, `num1`, and `num2`. The `operator` parameter specifies the arithmetic operation to perform on `num1` and `num2`. The `switch` statement checks the value of `operator` and performs the corresponding operation. If `operator` is not one of the specified values, the function returns an error message.

Comment if you have any doubts or suggestions on this JS switch case topic.

Note: The All JS Examples codes are tested on the Firefox browser and the Chrome browser.

OS: Windows 10

Code: HTML 5 Version

## 1 thought on “Calculator using switch case in JavaScript | Complete code”

1. hello, how can I use the switch statement to disable the alphabet keyboard?

console.log(event);

switch (event.key) {
case “C”:
case “Backspace”:
display.textContent = “”;
break;

case “ArrowUp”:
case “ArrowDown”:
case “ArrowLeft”:
case “ArrowRight”:
break;

case “=”:
display.textContent = eval(display.textContent);
break;

case “Enter”:
display.textContent = eval(display.textContent);
break;

default:
display.textContent += event.key;
}
});