// C Calculator Code
#include 

int main() {
    char op;
    float a, b;
    printf("Enter expression (e.g. 5 + 3): ");
    scanf("%f %c %f", &a, &op, &b);

    switch (op) {
        case '+': printf("%.2f\n", a + b); break;
        case '-': printf("%.2f\n", a - b); break;
        case '*': printf("%.2f\n", a * b); break;
        case '/': printf("%.2f\n", a / b); break;
        default: printf("Invalid operator\n");
    }
    return 0;
}

// C++ Calculator Code
#include 
using namespace std;

int main() {
    float a, b;
    char op;
    cout << "Enter expression (e.g. 5 + 3): ";
    cin >> a >> op >> b;

    switch (op) {
        case '+': cout << a + b; break;
        case '-': cout << a - b; break;
        case '*': cout << a * b; break;
        case '/': cout << a / b; break;
        default: cout << "Invalid operator";
    }
    return 0;
}

// Java Calculator Code
import java.util.Scanner;

public class Calculator {
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    System.out.print("Enter expression (a + b): ");
    double a = sc.nextDouble();
    char op = sc.next().charAt(0);
    double b = sc.nextDouble();

    switch (op) {
      case '+': System.out.println(a + b); break;
      case '-': System.out.println(a - b); break;
      case '*': System.out.println(a * b); break;
      case '/': System.out.println(a / b); break;
      default: System.out.println("Invalid operator");
    }
  }
}

# Python Calculator Code
a = float(input("Enter first number: "))
op = input("Enter operator (+, -, *, /): ")
b = float(input("Enter second number: "))

if op == '+':
    print(a + b)
elif op == '-':
    print(a - b)
elif op == '*':
    print(a * b)
elif op == '/':
    print(a / b)
else:
    print("Invalid operator")

// JavaScript (used in this calculator)
function append(value) {
  if (display.innerText === "0") display.innerText = value;
  else display.innerText += value;
}

function clearDisplay() {
  display.innerText = "0";
}

function calculate() {
  try {
    display.innerText = eval(display.innerText);
  } catch {
    display.innerText = "Error";
  }
}