Helper Boundaries

A helper function gives one calculation a clear boundary and name.

helper_boundaries.cpp

#include <iostream>

int applyDiscount(int price, int percent) {
    return price - (price * percent / 100);
}

int main() {
    int price = ;

    int discount = 25;
    int finalPrice = applyDiscount(price, discount);

    std::cout << "price=" << price << std::endl;
    std::cout << "discount=" << discount << std::endl;
    std::cout << "finalPrice=" << finalPrice << std::endl;
    return 0;
}

#include <iostream>

int applyDiscount(int price, int percent) {
    return price - (price * percent / 100);
}

int main() {
    int price = ;

    int discount = 25;
    int finalPrice = applyDiscount(price, discount);

    std::cout << "price=" << price << std::endl;
    std::cout << "discount=" << discount << std::endl;
    std::cout << "finalPrice=" << finalPrice << std::endl;
    return 0;
}

#include <iostream>

int applyDiscount(int price, int percent) {
    return price - (price * percent / 100);
}

int main() {
    int price = ;

    int discount = 25;
    int finalPrice = applyDiscount(price, discount);

    std::cout << "price=" << price << std::endl;
    std::cout << "discount=" << discount << std::endl;
    std::cout << "finalPrice=" << finalPrice << std::endl;
    return 0;
}

helper Move repeated or named work into a helper when the name explains the rule.

boundary The caller supplies inputs, the helper returns a result, and the main flow stays readable.