使用标准名称空间

 

1.using std::count;

 1 int main(int argc, char *argv[])
 2 {
 3     using std::count;
 4     using std::endl;
 5     using std::cin;
 6     char response;
 7     cin >> response;
 8     std::cout << response;
 9     return 0;
10 }

2.using namespace std;

1 int main(int argc, char *argv[])
2 {
3     using namespace std;
4     char response;
5     cin >> response;
6     std::cout << response;
7     return 0;
8 }