Why we don't use string header file in this snippet

Question

#include <iostream>
using namespace std;

class Birthday {
public:
Birthday(int m, int d, int y)
: month(m), day(d), year(y)
{ }
void printDate()
{
cout<<month<<"/"<<day <<"/"<<year<<endl;
}
private:
int month;
int day;
int year;
};

class Person {
public:
Person(string n, Birthday b)
: name(n), bd(b)
{ }
void printInfo()
{
cout << name << endl;
bd

Answer 1

In some compilers, <string> is included in <iostream>. That said, it is a good practice to explicitly include <string> when you need to utilize the string class.