Build a Simple Calculator with C++: A Step-by-Step Guide
Understanding the Basics
Before diving into the code, make sure you have a solid grasp of the following C++ concepts:
The Program in Action
This program prompts the user to enter an arithmetic operator (+, -, *, /) and two operands. The operator is stored in the op variable, while the two operands are stored in num1 and num2, respectively.
#include <iostream>
int main() {
char op;
double num1, num2;
std::cout << "Enter an operator (+, -, *, /): ";
std::cin >> op;
std::cout << "Enter two operands: ";
std::cin >> num1 >> num2;
//...
}The Switch Statement: The Heart of the Program
The switch statement is used to check the operator entered by the user. If the user enters +, the program executes the statements for case '+' and terminates. Similarly, if the user enters -, the program executes the statements for case '-' and terminates. This process is repeated for the * and / operators.
switch (op) {
case '+':
std::cout << "Result: " << num1 + num2 << std::endl;
break;
case '-':
std::cout << "Result: " << num1 - num2 << std::endl;
break;
case '*':
std::cout << "Result: " << num1 * num2 << std::endl;
break;
case '/':
if (num2!= 0)
std::cout << "Result: " << num1 / num2 << std::endl;
else
std::cout << "Error: Division by zero!" << std::endl;
break;
default:
std::cout << "Error: Invalid operator!" << std::endl;
}Error Handling: A Crucial Aspect
But what happens if the user enters an operator that doesn’t match any of the four characters (+, -, *, /)? In this case, the default statement is executed, displaying an error message.
Putting it All Together
With these building blocks in place, you’re ready to create your own simple calculator using C++. Take the first step towards becoming a proficient programmer and give it a try!
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