Question

Q#1: Take a real-world scenario and Implement it in C++ program. Your program
should consist of the following:
1. Constructors
2. Pointers
3. Private and Public keywords
4. Reference by return
5. Const keyword
6. Passing Object as argument

Answer 1

Points to consider before starting:

• Here, I have taken the real-world example of the shirt industry.
• I have considered "Black" as the best colour for the shirt.
• The default size of a shirt is "Medium".
• The default colour of the shirt is "White".

Please refer to the comments of the program for implementation of all and for more clarity.

#include<bits/stdc++.h>
using namespace std;

// Global variable
int numReferenceByReturn;

// Function declaration
int& funcReferenceByReturn();

class shirt {
public:  // Use of public key word
    string shirt_color, shirt_size;

    // Use of constructor
    // Default Constructor
    shirt()
    {
        shirt_color = "White";
        shirt_size = "Medium";
    }
private: // Use of private keyword
    tailor(string shirt_size) const  // Use of const keyword
    {
        // Calculation of cost
        int cost = 0;
        if(shirt_size == "Medium")
            cost = 100;
        else if(shirt_size == "Large")
            cost = 150;
        else
            cost = 80;
    }
public:
    string best_colour = ""; // Initializing it as empty string

    void add(shirt s)
    {
        best_colour = best_colour + s.best_colour; // Adding the colors
    }
};

// Reference by return
int& funcReferenceByReturn()
{
    return numReferenceByReturn;
}

int main()
{
    // Using constructor
    shirt s;
    cout << "Shirt color: " << s.shirt_color << endl;
    cout << "Shirt size: " << s.shirt_size << endl;

    // Use of pointer
    int  v = 20;   // actual variable declaration.
    int  *i;        // pointer variable
    i = &v;       // store address of var in pointer variable

    cout << "\nValue of v variable: ";
    cout << v << endl;

    // Reference by return
    funcReferenceByReturn() = 5;
    cout << "\nValue of numReferenceByReturn: " << numReferenceByReturn << endl;
    s.best_colour = "Black";

    // Passing Object as argument
    shirt s1;
    s1.add(s);
    cout << "\nBest color: " << s1.best_colour << endl; // Printing the value we get after passing Object as argument

    return 0;
}

Output after running the above program:

Please let me know in the comments in case of any confusion. Also, please upvote if you like.