IN C++ help adding functions

My program is a library management program, for option 5 when you search for a book i want it so that it shows the availability and who borrowed the book.

Currently, option 5 only shows availability.

Second change is for option 6 not to list how many books a user has borrowed but the names of the book borrowed. (feel free to change the menu and formatting)

currently, option 6 only shows the number of books borrowed.

CODE:

#include

#include

using namespace std;

//structure to store library data

class BookDetails

{

public: //function 5

struct library//book data for one book

{

int code;

char title[20];

int status;//availibility

};

library book_details[100];//total library capacity

};

//structure to store user data

class UserDetails : public BookDetails

{

public: //function 6

struct users//user data

{

int id;

char name[20];

int booksNumber;

};

users user_details[100];

};

int main()

{

UserDetails ob1;//variable of class userdetails

UserDetails *ob;//pointer of userdetails

ob = &ob1;//assign address of ob to ob1

int tempId, i, flag = 0, j;

char tempName[20];

int tempCode;

//variable to hold 100 userdetails

//variable to hold 100 book details

int user_count = 0, books_count = 0;

int choice;

//this loop runs until 7 is entered

do

{

cout << "*************MENU************* ";

cout << "1. Add a new book ";

cout << "2. Add a new user ";

cout << "3. Borrow a book ";

cout << "4. Return a book ";

cout << "5. Search a book ";

cout << "6. Display user info ";

cout << "7. Exit ";

while (1)

{

cout << "Enter your choice : ";

cin >> choice;

if (cin.fail())//for invalid inputs

{

cin.clear();//clears the error state

cin.ignore(numeric_limits::max(), ' ');//discard input

cout << "You have entered wrong input.Please enter a valid Integer ";

}

else

break;

}

switch (choice)

{

//Adds a new book in to the database and increase book count by 1

case 1:

cout << "**********ADD A BOOK********** ";

cout << "Bookname : ";

//cin.ignore() is used to clean the buffer to take input

cin.ignore();

//cin.getline is used to take input with space. Enter key is used to finish taking input. 100 is size of input character

cin.getline(ob->book_details[books_count].title, 100);

cout << "Bookcode : ";

cin >> ob->book_details[books_count].code;

while (true)

{

bool taken = false;//a new unique book

int code = ob->book_details[books_count].code;

// iterate over all book codes

for (int i = 0; i < books_count; i++)//to find if the book code is taken

{

// if book code is already taken

if (ob->book_details[i].code == code)

{

taken = true;

cout << "Book ID already taken ";

cout << "Bookcode : ";

cin >> ob->book_details[books_count].code;//enters new code

break;

}

}

if (!taken)

break;

}

ob->book_details[books_count].status = 1;

books_count++;//adds to book count

break;

case 2:

//adds a new user details in to database

cout << "**********ADD A USER********** ";

cout << "Enter UserId : ";

cin >> tempId;

//flag variable to check whether user exists or not

flag = 1;//username not taken

for (i = 0; i < user_count; i++)

{

if (tempId == ob->user_details[i].id)//to find if userid has been used

{

cout << "UserId already taken ";

flag = 0;

break;

}

}

//if user is not taken creating user id and increase user_count by 1

if (flag)

{

ob->user_details[user_count].id = tempId;

cout << "Enter Username : ";

cin.ignore();

cin.getline(ob->user_details[user_count].name, 100);

ob->user_details[user_count].booksNumber = 0;

cout << "Welcome "<< ob->user_details[user_count].name <<" ";

user_count++;

}

break;

case 3:

cout << "*********BORROW A BOOK******** ";

cout << "Please enter your userId : ";

cin >> tempId;

flag = 0;

//check whether user exists or not using flag variable

for (i = 0; i < user_count; i++)

{

if (ob->user_details[i].id == tempId)

{

flag = 1;

break;

}

}

//if user exists then print his name and check for the requested book

if (flag)

{

cout << "Welcome " << ob->user_details[i].name << " ";

//if user has taken less than 5 books

if (ob->user_details[i].booksNumber <= 5)

{

cout << "Please enter book code you want to borrow : ";

cin >> tempCode;

for (j = 0; j < 100; j++)

{

if (ob->book_details[j].code == tempCode && ob->book_details[j].status != 0)//find the book and check the availibility

{

ob->book_details[j].status = 0;//sets availability to unavailable

ob->user_details[i].booksNumber++;//adds one to user books borrowed

flag = 0;

break;

}

}

if (flag)//cannot find book in book detail

{

cout << "Book not found or it has been currently borrowed ";

}

else

{

cout << "thank you for borrowing a book ";

}

}

else

{

cout << "Username incorrect ;";

}

}

break;

case 4:

// to return the book issued to a user

cout << "*********RETURN A BOOK******** ";

cout << "Please enter book code :";

cin >> tempCode;

flag = 0;

for (i = 0; i < user_count; i++)

{

if (ob->book_details[i].code == tempCode)//searches through database for book

{

flag = 1;

break;

}

}

//once book is found then check for user id

if (flag)

{

if (ob->book_details[i].status == 0)//checks if book already borrowed

{

cout << "Enter user id: ";

cin >> tempId;

flag = 0;

for (j = 0; j < user_count; j++)

if (ob->user_details[j].id == tempId)

//if user exists

{

flag = 1;

break;

}

//if user and book details are found

if (flag)

{

ob->user_details[j].booksNumber--;

//user # of books borrowed goes down by 1

ob->book_details[i].status = 1;

//book becomes available

}

else

{

cout << "User not found ";

}

}

else

{

cout << "Book hasn't been borrowed ";

}

}

else

{

cout << "Invalid code ";

}

break;

case 5:

//Searching a book using bookcode

cout << "*********SEARCH A BOOK******** ";

cout << "Enter book code : ";

cin >> tempCode;

cout << "Book ID Book Name Availability ";

for (i = 0; i < 100; i++)

{

if (ob->book_details[i].code == tempCode)

//if book exists

{

cout << ob->book_details[i].code << "\t" << ob->book_details[i].title << "\t" << ob->book_details[i].status << " ";

break;

}

}

cout<<"This book does not exist ";

break;

case 6:

//printing details of user using user_details structure

cout << "*****DISPLAY ALL USER INFO**** ";

cout << "UserID UserName Books borrowed ";

for (i = 0; i < user_count; i++)

{

cout << ob->user_details[i].id << "\t" << ob->user_details[i].name << "\t" << ob->user_details[i].booksNumber << " ";

}

cout << " ";

break;

case 7:

cout << "*************EXIT************* ";

cout << "Thank you for using the library!";

break;

//if user input doesnot match with any of the case then ask him to enter data again

default:

cout << "Please enter valid input ";

}

} while (choice != 7);

return 0;

}