#include<iostream>
#include<string>
using namespace std;
int main()
{
string name;
cout << "input your name,please:" << endl;
getline(cin, name);//using function_getline to input NULL to name.
if(name.empty())//empty() is NULL
{
cout << "input is null..." << endl;
system("pause");
return 0;
}
else if(name=="Henry")
{
cout <<"you're an administrator."<<endl;
}
cout << "Hello Uesr " << name<<"!" << endl;
cout << "your name length is:" << name.size() << endl;
cout << "your name first letter is:" << name[0] << endl;
system("pause");
return 0;
}