c++-域运算符::

(1)用于对与局部变量同名的全局变量进行访问

#include <iostream>using namespace std;int var =100;int main(){int var = 50;cout<<var<<endl;            //50cout<<::var<<endl;          //100，可以用域运算符来访问全局变量return 0;}

(2)用于表示类的成员函数

class Student{public:int age_;string name_;void setAge(int age);int getAge();};void Student::setAge(int age) //域运算符{age_ = age;}int Student::getAge() //域运算符{cout<<age_<<endl;return age_;}