C++ - vector<string> 복사 & cout 으로 출력

#include <string>
#include <vector>
#include <iostream>
using namespace std;


int main() {
    vector<string> s1{ "hello","hi" };
    vector<string> s2 = s1;
    cout << *s2.begin();
}

또는

#include <string>
#include <vector>
#include <iostream>
using namespace std;


int main() {
    vector<string> s1{ "hello","hi" };
    vector<string> s2 = s1;
    vector<string>::iterator iter;
    iter = s2.begin();
    cout << *iter;
}

또는

#include <string>
#include <vector>
#include <iostream>
using namespace std;

int main() {
	vector<string> s1{ "hello","hi" };
	vector<string> s2 = s1;
	cout << s2.at(0);
}

=> hello 가 출력됨