当我到达字符串中的某个字符时，如何打印？

str = "Hello, World!"
index = 7
print(str[index])

String str = "Hello, World!";
int index = 7;
System.out.println(str.charAt(index));

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

int main() {
    string str = "Hello, World!";
    int index = 7;
    cout << str[index] << endl;
    return 0;
}