#include<iostream>

#include<string>

using namespace std;

int main(){

string name;

cout<<"Please input your name:"<<endl;

getline(cin,name);

if(name.empty()){

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

system("pause");

return 0;

}

if(name=="imooc"){

cout<<"you are a administrate"<<endl;

}

cout<<"hello"+name<<endl;

cout<<"your name length"<<name.size()<<endl;

cout<<"your name first letter is:"<<name[0]<<endl;

system("pause");

return 0;

}

string初始化