qfedu-cpp-level/day1/d2.cpp

#include <iostream>

using namespace std;

int x = 200;
int main()
{
    int x = 100;
    cout << "x = " << x << endl;
    // ::x 表示全局的 x
    cout << "全局的 x = " << ::x << endl;
    return 0;
}