Return Values

Overview

Functions can send data back to the caller using the `return` statement. The return type (e.g., int, void, double) must be declared in the signature.

Syntax

cpp

// Returns an integer
int getSquare(int x) {
    return x * x;
}

// Returns nothing
void logMessage(string msg) {
    cout << "LOG: " << msg;
    // return; is optional in void functions
}

Common Pitfalls

Forgetting to return a value in a non-void function (Undefined Behavior).
Returning a pointer or reference to a local variable that gets destroyed when the function ends.

Interview Tips

In modern C++, you can use `auto` as a return type, and the compiler will deduce it based on the `return` statement.

Real-World Example

Using a returned value in a calculation.

example

cpp

#include <iostream>
using namespace std;

double calculateTax(double amount) {
    return amount * 0.08;
}

int main() {
    double price = 100.0;
    double total = price + calculateTax(price);
    cout << "Total cost: $" << total << endl;
    return 0;
}

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