C++ program to hold student info using data hiding and encapsulation

Suppose we want to make student data type with data hiding and encapsulation. Students must have first_name, last_name, age and class items, but these variables cannot be accessible directly. We shall have to define some functions like get_firstname() set_firstname(), get_age() set_age() etc to retrieve and update variable values, and a to_string() function to display students details in this format (age, first_name, last_name, class). From the console take four parameters as input and set them using setter methods that we have defined, and show each items using getter methods and finally using to_string() method.

So, if the input is like

priyam
kundu
16
10

then the output will be

16
priyam
kundu
10

(16, priyam, kundu, 10)

To solve this, we will follow these steps −

• define a class with first_name, last_name of type string and age, cl of type integer

• define getter functions for all attributes

• define setter functions for all attributes

• define to_string() function using string-stream object and create formatted string that matches to the output format

• From the main method do the following −

• read each line and store first_name, last_name, age, cl respectively

• call setter functions to set these values into the class members

• print all attribute using getter methods;

• display student info in this format (age, first_name, last_name, cl) using to_string() function.

Example

Let us see the following implementation to get better understanding −

#include <iostream>
#include <sstream>
using namespace std;
class Student{
    private:
    int age, cl;
    string first_name, last_name;
    public:
    int get_age(){return age;}
    int get_class(){return cl;}
    string get_firstname(){return first_name;}
    string get_lastname(){return last_name;}
    void set_age(int a){age = a;}
    void set_class(int c){cl = c;}
    void set_firstname(string fn){first_name = fn;}
    void set_lastname(string ln){last_name = ln;}
    string to_string(){
        stringstream ss;
        ss << "(" << age << ", " << first_name << ", " << last_name << ", " << cl << ")";
       
        return ss.str();
    }
};
int main() {
    Student stud;
    int age, cl;
    string first_name, last_name;
    cin >> first_name >> last_name >> age >> cl;
    stud.set_age(age);
    stud.set_class(cl);
    stud.set_firstname(first_name);
    stud.set_lastname(last_name);
    cout << stud.get_age() << endl;
    cout << stud.get_firstname() << endl;
    cout << stud.get_lastname() << endl;
    cout << stud.get_class() << endl;
    cout << endl << stud.to_string();
}

Input

priyam
kundu
16
10

Output

16
priyam
kundu
10

(16, priyam, kundu, 10)