#define AGE 25

class Person{
  private:
    String _name;
    int _age;
  
  public:
  Person(){}
  Person(char *name);                  // alternative way is to use Person(String name);  or something like char[25];
  Person(char *name, int age);
};

Person::Person(char *name){
  _name = name;
  Serial.print("Person name: "); Serial.println(_name);
  Serial.print("Person age: "); Serial.println(_age);
}
Person::Person(char *name, int age){
  _name = name;
  _age = age;
  Serial.print("Person name: "); Serial.println(_name);
  Serial.print("Person age: "); Serial.println(_age);
}

void setup() {
Serial.begin(115200);
Person john("John", 55);
Person jack ("Jack");
}

void loop() {
}