encapsulation.cpp

//This example demonstrates encapsulation, data protection, and object interaction

/*


#include <iostream>
using namespace std;

class BankAccount
{
private:
    int balance;
    string accountHolder;
    int accountNumber;
    static int totalAccounts;    // Shared by all objects

public:
    // Constructor
    BankAccount(string name, int initialBalance)
    {
        accountHolder = name;
        balance = initialBalance;
        totalAccounts++;
        accountNumber = totalAccounts;
        cout << "Account created for " << name << " (A/C No: " << accountNumber << ")" << endl;
    }

    void deposit(int amount)
    {
        if(amount > 0)
        {
            balance += amount;
            cout << "Deposited: Rs " << amount << endl;
        }
        else
        {
            cout << "Invalid amount!" << endl;
        }
    }

    void withdraw(int amount)
    {
        if(amount <= 0)
        {
            cout << "Invalid amount!" << endl;
        }
        else if(amount <= balance)
        {
            balance -= amount;
            cout << "Withdrawn: Rs " << amount << endl;
        }
        else
        {
            cout << "Insufficient balance!" << endl;
        }
    }

    void showBalance()
    {
        cout << "Account Holder: " << accountHolder << endl;
        cout << "Account Number: " << accountNumber << endl;
        cout << "Current Balance: Rs " << balance << endl;
        cout << "------------------------" << endl;
    }

    static void showTotalAccounts()
    {
        cout << "Total bank accounts: " << totalAccounts << endl;
    }
};

// Initialize static member
int BankAccount::totalAccounts = 0;

int main()
{
    BankAccount acc1("Rahul Sharma", 5000);
    BankAccount acc2("Priya Patel", 10000);

    acc1.deposit(2000000);
    acc1.withdraw(1000);
    acc1.showBalance();

    acc2.withdraw(15000000);    // Attempting to withdraw more than balance
    acc2.showBalance();

    BankAccount::showTotalAccounts();    // Calling static function

    return 0;
}


*/


//without encapsulation



#include <iostream>
using namespace std;

class Student {
public:
    int marks;
};

int main() {
    Student s1;

    s1.marks = 85;   // directly accessing variable

    cout << "Marks: " << s1.marks << endl;

    return 0;
}


// with encapsulation

#include <iostream>
using namespace std;

class Student {
private:
    int marks;

public:
    void setMarks(int m) {
        marks = m;
    }

    void displayMarks() {
        cout << "Marks: " << marks << endl;
    }
};

int main() {
    Student s1;

    s1.setMarks(85);     // setting value through function
    s1.displayMarks();   // displaying value

    return 0;
}