tut22.cpp

#include <iostream>
#include <string>

using namespace std;

class binary
{
    string s; // by default it is private
    // void chk_bin(void); // if it is in private, then it cannot be used through main function.

public:
    void read(void);
    void chk_bin(void);
    void ones_compliment(void);
    void display(void);
};

void binary ::read(void)
{
    cout << "Enter a binary number: ";
    cin >> s;
}

void binary ::chk_bin(void)
{
    for (int i = 0; i < s.length(); i++)
    {
        if (s.at(i) != '0' && s.at(i) != '1')
        {
            cout << "Incorrect binary format" << endl;
            exit(0);
        }
    }
}

void binary ::ones_compliment(void)
{

    for (int i = 0; i < s.length(); i++)
    {
        if (s.at(i) == '0')
        {
            s.at(i) = '1';
        }
        else if (s.at(i) == '1')
        {
            s.at(i) = '0';
        }
    }
}

void binary ::display(void)
{
    chk_bin(); // example of Nesting of Member Functions
    cout << "displaying your binary number: " << endl;
    for (int i = 0; i < s.length(); i++)
    {
        cout << s.at(i);
    }
    cout << endl;
}

int main()
{

    // OOPS Recap and Nesting of Member Functions:

    // Nesting of Member Functions

    binary b;
    b.read();
    // b.chk_bin();
    b.display();
    b.ones_compliment();
    b.display();

    return 0;
}