Namespace Basics

A namespace groups related names so they do not crowd the global scope.

namespace_basics.cpp

#include <iostream>

namespace math_tools {
int doubleValue(int number) {
    return number * 2;
}
}

int main() {
    int value = ;

    int result = math_tools::doubleValue(value);

    std::cout << "value=" << value << std::endl;
    std::cout << "result=" << result << std::endl;
    return 0;
}

#include <iostream>

namespace math_tools {
int doubleValue(int number) {
    return number * 2;
}
}

int main() {
    int value = ;

    int result = math_tools::doubleValue(value);

    std::cout << "value=" << value << std::endl;
    std::cout << "result=" << result << std::endl;
    return 0;
}

#include <iostream>

namespace math_tools {
int doubleValue(int number) {
    return number * 2;
}
}

int main() {
    int value = ;

    int result = math_tools::doubleValue(value);

    std::cout << "value=" << value << std::endl;
    std::cout << "result=" << result << std::endl;
    return 0;
}

namespace A namespace wraps functions, types, or variables inside a named group.