c++, for

# include <iostream>

# include <string>

int main(void) {

std::string s = "hello world";

for (unsigned int i = 0; i < s.length(); i++) {

std::cout << s[i] << std::endl;

}

std::cout << std::endl;

for (char data : s) {

std::cout << data << std::endl;

}

}