C++ - Unable to inherit from base class | Gives empty values - c++

Question

I guess I am doing something wrong here in the below code. I want to inherit the methods of class Person in class Employee.
#include<bits/stdc++.h>
using namespace std;
class Person{
private:
string name;
int age;
public:
Person(string name, int age){ //Base parameterized constructor
name = name;
age = age;
}
void getName(){
cout<<"Name: "<<name<<endl;
}
void getAge(){
cout<<"Age: "<<age<<endl;
}
};
class Employee: public Person{ //Default inheritance type is private
private:
int employeeID;
public:
Employee(string name, int age, int id) : Person(name, age){ //Derived parameterized constructor
employeeID = id;
}
void getEmployeeDetails(){
getName();
getAge();
cout<<"Employee ID: "<<employeeID<<endl;
}
};
int main(){
Employee* e = new Employee("John", 24, 14298);
e->getEmployeeDetails();
return 0;
}
I am getting the below output:
Name:
Age: 0
Employee ID: 14298
Please let me know what am I missing here. Any help would be appreciated!

Answer 1

The issue is not with inheritance, but with the fact that Person never initializes any of its fields.
This code:
Person(string name, int age){ //Base parameterized constructor
name = name;
age = age;
}
assigns local variable name to itself and same with age, because parameters shadow class member names. Member objects with the same name are never initialized.
Three solutions possible (listed in subjective order in which I prefer them):
Use member initializer list to initialize your members:
Person(string name, int age) : name{name}, age{age}
{
}
Use different names
Person(string providedName, int providedAge)
{
name = providedName;
age = providedAge;
}
Use this to disambiguate objects
Person(string name, int age){ //Base parameterized constructor
this->name = name;
this->age = age;
}

Answer 2

Nothing to do with inheritance, the code would have been wrong anyway.
This
Person(string name, int age){ //Base parameterized constructor
name = name;
age = age;
}
should be this
Person(string n, int a){
name = n;
age = a;
}
Because your constructor parameter declaration names are the same as your member variables, the member variables are hidden and you were just assigning the parameters to themselves.
A better way to write the same code is to use an initialiser list
Person(string name, int age) : name(name), age(age)
}
Initialiser lists have a couple of advantages, one of them is that there's no ambiguity, you can have the parameter names the same as the member variable names. The other (more important) is that in general, initialisation is more efficient than assignment.