#include<iostream>

#include<stdlib.h>

#include<string>

using namespace std;

int main()

{

string name; // 1

cout<<"please input your name:";  // 2

getline(cin,name);

if(name.empty()) //6

{

cout<<"input is null.."<<endl;

system("pause");

   return 0;

}

if(name=="imooc") //7

{

cout<<"you are an administrator"<<endl;

}

cout<<"hello" + name<<endl;  //3

cout<<"your name length:"<<name.size<<endl; //4

cout<<"your name fisrt lettor is:"<<name[0]<<endl; //5

system("pause");

return 0;

}