c++ beginner s4-class

//Person.h

#ifndef PERSON_H_
#define PERSON_H_

#include <iostream>
using namespace std;

class Person {
private:
    string name;
    int age;
    int height;

public:
    // construct init list
    Person(): name("unnamed"), age(0) {};
    Person(string name): name(name), age(0) {};

    // constructor by this
    Person(string name, int age);

    // getter / setter
    void setHeight(int height);
    string getHeight();

    // methods
    string toString();
};

#endif /* PERSON_H_ */

// Person.cpp

#include "Person.h"
#include <sstream>

// constructor by this
Person::Person(string name, int age) {
    this->name = name;
    this->age = age;
}

// getter / setter
void Person::setHeight(int newHeight) {
    height = newHeight;
}

string Person::getHeight() {
    return to_string(height);
}

// methods
string Person::toString() {
    stringstream ss;

    ss << "Name: ";
    ss << name;
    ss << "; age: ";
    ss << age;

    return ss.str();
}

// main.cpp

#include <iostream>
#include "Person.h"
using namespace std;

int main() {

    Person person1;
    Person person2("Bob");
    Person person3("Sue", 25);
    person3.setHeight(165);

    cout << person1.toString() <<  endl;
    cout << person2.toString() <<  endl;
    cout << person3.toString() << ", and she is " << person3.getHeight() << " cm height." << endl;

    return 0;
}