1.::作用域运算符

::双冒号为全局运算符

#include <iostream>
using namespace std;

int atk = 200;

void Test()
{
    int atk = 100;
    cout << "Test内部：" << atk << endl;
    cout << "Test外部：" << ::atk << endl;
}

int main()
{
    Test();
    system("Pause");
    return EXIT_SUCCESS;
}

结果