#include 
using namespace std;

// Function to perform calculations
double calculate(double a, double b, char op) {
    switch(op) {
        case '+':
            return a + b;
        case '-':
            return a - b;
        case '*':
            return a * b;
        case '/':
            if(b != 0) return a / b;
            else {
                cout << "Error: Division by zero!" << endl;
                return 0;
            }
        default:
            cout << "Error: Invalid operator!" << endl;
            return 0;
    }
}

int main() {
    double num1, num2, result;
    char operation;
    
    cout << "Enter first number: ";
    cin >> num1;
    
    cout << "Enter operator (+, -, *, /): ";
    cin >> operation;
    
    cout << "Enter second number: ";
    cin >> num2;
    
    result = calculate(num1, num2, operation);
    cout << "Result: " << result << endl;
    
    return 0;
}
    

1. What Is A C++ Calculator?

A simple calculator in C++ is a program that performs basic arithmetic operations (addition, subtraction, multiplication, division) using switch statements or functions to handle different mathematical operations.

2. How The Calculator Works

The calculator program takes two numbers and an operator as input, then uses conditional logic (switch statement) to determine which arithmetic operation to perform.

Key Components:

• Input handling for numbers and operator
• Switch statement for operation selection
• Error handling for division by zero
• Output display of results

3. Switch Statement Implementation

The switch statement provides an efficient way to handle multiple operation cases without complex if-else chains. Each case corresponds to a specific arithmetic operation.

switch(operation) {
    case '+': result = num1 + num2; break;
    case '-': result = num1 - num2; break;
    case '*': result = num1 * num2; break;
    case '/': 
        if(num2 != 0) result = num1 / num2;
        else cout << "Division by zero error";
        break;
    default: cout << "Invalid operator";
}
                    

4. Function-Based Approach

Using functions makes the code more modular and reusable. Each arithmetic operation can be implemented as a separate function that can be called from the main program.

double add(double a, double b) { return a + b; }
double subtract(double a, double b) { return a - b; }
double multiply(double a, double b) { return a * b; }
double divide(double a, double b) { 
    return (b != 0) ? a / b : 0; 
}
                    

5. Frequently Asked Questions (FAQ)

Q1: Why use switch statements instead of if-else?
A: Switch statements are more efficient and readable when checking a single variable against multiple constant values.

Q2: How to handle invalid input?
A: Use input validation and the default case in switch statements to handle unexpected operator values.

Q3: Can this calculator handle decimal numbers?
A: Yes, by using double or float data types instead of integers for number variables.

Q4: How to extend the calculator for more operations?
A: Simply add more cases to the switch statement or create additional functions for new operations.

Q5: What about operator precedence?
A: This simple calculator processes operations sequentially. For complex expressions, you'd need to implement parsing and precedence rules.