Namespace Helpers

A namespace groups helper names so a small project can avoid accidental collisions.

namespace_helpers.cpp

#include <iostream>

namespace billing {
int addFee(int amount, int fee) {
    return amount + fee;
}
}

int main() {
    int subtotal = ;

    int fee = 4;
    int total = billing::addFee(subtotal, fee);

    std::cout << "subtotal=" << subtotal << std::endl;
    std::cout << "fee=" << fee << std::endl;
    std::cout << "total=" << total << std::endl;
    return 0;
}

#include <iostream>

namespace billing {
int addFee(int amount, int fee) {
    return amount + fee;
}
}

int main() {
    int subtotal = ;

    int fee = 4;
    int total = billing::addFee(subtotal, fee);

    std::cout << "subtotal=" << subtotal << std::endl;
    std::cout << "fee=" << fee << std::endl;
    std::cout << "total=" << total << std::endl;
    return 0;
}

#include <iostream>

namespace billing {
int addFee(int amount, int fee) {
    return amount + fee;
}
}

int main() {
    int subtotal = ;

    int fee = 4;
    int total = billing::addFee(subtotal, fee);

    std::cout << "subtotal=" << subtotal << std::endl;
    std::cout << "fee=" << fee << std::endl;
    std::cout << "total=" << total << std::endl;
    return 0;
}

namespace Namespaces give related functions a shared prefix without putting everything into one global name pool.

qualification Calling `billing::addFee` makes the helper's ownership visible at the call site.