作用域解析运算符

#if 0
#define _CRT_SECURE_NO_WARNINGS
#include<iostream>
using namespace std;
int g_number = 100;

void test01()
{
    int g_number = 200;
    cout << g_number << endl;
    // 打印作用于 全局的变量
    cout << ::g_number << endl;
}

class MyClass{
public:
    const static int a = 10;
};

void test02(){
    cout << MyClass::a << endl;//某个函数作用域的内的东西访问出来
/* 底层实现机制不清楚   */
}

int main(){
    test01();
    system("pause");
    return EXIT_SUCCESS;

}
#endif