#include <iostream> #include <string> using namespace std; //使用friend关键字让外部函数DisplayAge()能够访问私有数据成员 class Humen { public: Humen(string name, int age) :m_strName(name), m_nAge(age) { } private: string m_strName; int m_nAge; friend void DisplayAge(const Humen& person); }; void DisplayAge(const Humen& person) { cout<<"age : "<<person.m_nAge<<endl; } int main() { Humen person("xxx", 11); DisplayAge(person); system("pause"); return 0; }
#include <iostream> #include <string> using namespace std; //使用friend关键字让外部类Utility能够访问私有数据成员 class Humen { public: Humen(string name, int age) :m_strName(name), m_nAge(age) { } private: string m_strName; int m_nAge; friend class Utility; }; class Utility { public: static void DisplayAge(const Humen& person) { cout<<"age : "<<person.m_nAge<<endl; } }; int main() { Humen person("xxx", 11); Utility::DisplayAge(person); system("pause"); return 0; }