Why can't I use string here instead of char array?

Question

#include<iostream>
#include<cstdlib>
#include<ctime>
using namespace std;

void password(){
srand(time(0));
string chars = "Ab124*&";
char pass[10];
for (int i = 0; i < 10; i++)
pass[i] = chars[rand()%7];
cout << pass;
}
main(){
password();
}

In the above code, I've used 'char pass[10]' as a character array. Instead, if I declare 'string pass' or 'string pass = "\0" ', the code doesn't work. But if I initialise the string to any other random value for example, 'string pass = "45in4tnwri" ', then the code works. Why is it so?

Answer 1

When you do

string pass;

without initializing anything, you cannot use it as an array because no size is specified explicitly or implicitly. If you want to use string, do it as such:

#include<iostream>
#include<cstdlib>
#include<ctime>
using namespace std;

void password(){
srand(time(0));
string chars = "Ab124*&";
string pass;

for (int i = 0; i < 10; i++)
pass += chars[rand()%7];
cout << pass;
}
int main(){
password();
}