add: 14_file_handling 07

Author: webwithaman

.vscode/settings.json

@@ -2,7 +2,6 @@
 
 // // Header files
 #include <iostream>
-
 #include <string.h>
 
 // // use namespace
@@ -64,13 +63,13 @@ class Book
     // // instance member function to set Book Title
     void setBookTitle(char *bookTitle)
     {
-        strcpy(bookTitle, bookTitle);
+        strcpy(this->bookTitle, bookTitle);
     }
 
     // // instance member function to get Book Title
     char *getBookTitle(char *bookTitle)
     {
-        strcpy(bookTitle, bookTitle);
+        strcpy(bookTitle, this->bookTitle);
         return bookTitle;
     }
 };

05_constructors_and_overloading/11_book.cpp

@@ -16,10 +16,7 @@
 
 06. Write a C++ program that counts the total number of characters, words and lines in the file.
 
-07. There are 50 records in a file. Each record contains 6-character item-code, 20
-characters for item-name and an integer price. Write a program to read these
-records, arrange them in the descending order of price and write them in the same
-file, overwriting the earlier records.
+07. Define a cpp class Book having attributes bookId, bookTitle and bookPrice and appropriate getters and setters. Now, get n number of book records from user and store each record in a file names "books_data.dat" and then read data from file and display.
 
 08. A file 'Employee.txt' contains empno and empname. Write a C++ program to add and
 read contents of this file and search for an employee whose name is 'XYZ'.

14_file_handling/00_questions.txt

@@ -0,0 +1,219 @@
+// // Define a cpp class Book having attributes bookId, bookTitle and bookPrice and appropriate getters and setters. Now, get n number of book records from user and store each record in a file names "books_data.dat" and then read data from file and display
+
+// // Header files
+#include <iostream>
+#include <fstream>
+#include <cstring>
+
+// // use namespace
+using namespace std;
+
+#define MAX_BOOKS 50
+
+// // define class Book
+class Book
+{
+public:
+    // // static member variable
+    static const unsigned int MAX_CHARS_IN_TITLE = 31;
+
+private:
+    // // instance member variables
+    unsigned int bookId;
+    char bookTitle[MAX_CHARS_IN_TITLE];
+    double bookPrice;
+
+public:
+    // // constructors
+    Book()
+    {
+        bookId = -1;
+        bookPrice = -1;
+        bookTitle[0] = 0;
+    }
+
+    Book(int bookId, const char *bookTitle, double bookPrice)
+    {
+        this->bookId = bookId;
+        strcpy(this->bookTitle, bookTitle);
+        this->bookPrice = bookPrice;
+    }
+
+    // // instance member function to set bookId
+    void setBookId(int bookId)
+    {
+        if (bookId < 0) // if bookId is negative make it positive
+            bookId = -bookId;
+
+        this->bookId = bookId;
+    }
+
+    // // instance member function to get bookId
+    unsigned int getBookId()
+    {
+        return bookId;
+    }
+
+    // // instance member function to set bookTitle
+    void setBookTitle(char *bookTitle)
+    {
+        strcpy(this->bookTitle, bookTitle);
+    }
+
+    // // instance member function to get bookTitle
+    const char *getBookTitle()
+    {
+        return bookTitle;
+    }
+
+    // // instance member function to set bookPrice
+    double setBookPrice(double bookPrice)
+    {
+        this->bookPrice = bookPrice;
+    }
+
+    // // instance member function to get bookPrice
+    double getBookPrice()
+    {
+        return bookPrice;
+    }
+
+    // // instance member function to input and set book data
+    void inputBookData()
+    {
+        int bookId;
+        char bookTitle[Book::MAX_CHARS_IN_TITLE];
+        double bookPrice;
+
+        // // Get book id
+        cout << "\nEnter Book Id => ";
+        cin >> bookId;
+
+        // // Get book title
+        cout << "\nEnter Book Title (MAX_CHARS " << Book::MAX_CHARS_IN_TITLE - 1 << ") => ";
+        cin.ignore();
+        cin.getline(bookTitle, Book::MAX_CHARS_IN_TITLE);
+
+        // // Get book price
+        cout << "\nEnter Book Price => ";
+        cin >> bookPrice;
+
+        // // set data
+        setBookId(bookId);
+        setBookTitle(bookTitle);
+        setBookPrice(bookPrice);
+    }
+
+    // // instance member function to show book data
+    void showBookData()
+    {
+        cout << "\nBook Id => " << bookId;
+        cout << "\nBook Title => " << bookTitle;
+        cout << "\nBook Price => " << bookPrice;
+    }
+
+    // // instance member function to store book record
+    int storeBookData()
+    {
+        if (bookId == -1 || bookPrice == -1)
+            return 0; // book data not stored
+
+        // // specify file name
+        const char *fileName = "books_data.dat";
+
+        // create an instance of ofstream for writing in a file
+        ofstream fout;
+
+        // // open file in binary mode for writing and append data
+        fout.open(fileName, ios::app | ios::binary);
+
+        // // check if the file is successfully opened
+        if (!fout.is_open())
+            return 0; // book data not stored
+
+        fout.write((char *)this, sizeof(*this));
+
+        return 1; // book data successfully stored
+    }
+};
+
+// // function to fetch books data from a fike and show
+void fetchAndShowBookData()
+{
+    // // specify file name
+    const char *fileName = "books_data.dat";
+
+    // create an instance of ifstream for reading from a file
+    ifstream fin;
+
+    // // open file in binary mode for reading
+    fin.open(fileName, ios::in | ios::binary);
+
+    // // check if the file is successfully opened
+    if (!fin.is_open())
+    {
+        cout << "\nError: Unable to Open File...";
+        return;
+    }
+
+    // // create an instance of Book to store fetched data
+    Book tempBook;
+
+    fin.read((char *)&tempBook, sizeof(tempBook));
+
+    while (!fin.eof())
+    {
+        cout << endl;
+        tempBook.showBookData();
+        cout << endl;
+        fin.read((char *)&tempBook, sizeof(tempBook));
+    }
+}
+
+// // Main Function Start
+int main()
+{
+    int n;
+
+    cout << "\nHow Many Books' Data You Want to Store (MAX " << MAX_BOOKS << ") => ";
+    cin >> n;
+
+    // // invalid input
+    if (n < 1 || n > MAX_BOOKS)
+    {
+        cout << "\n!!! Invalid Input..." << endl;
+        return 0;
+    }
+
+    // // dynamically allocate memory for n objects of Book
+    Book *books = new Book[n];
+
+    // // input, set and store books data
+    cout << "\n>>>>>>>>>> Enter Data of " << n << " Books <<<<<<<<<<<<<" << endl;
+    for (int i = 0; i < n; i++)
+    {
+        cout << "\n>>>>>>>>>>> Enter Data of Book " << i + 1 << " <<<<<<<<<<<<" << endl;
+
+        // // input and set book data
+        books[i].inputBookData();
+
+        // // store book data
+        if (!(books[i].storeBookData()))
+        {
+            cout << "\n!!! Book Data Not Stored..." << endl;
+            return 0;
+        }
+    }
+
+    // // books data stored successfully
+    cout << "\nBooks Data Successfully Stored..." << endl;
+
+    // // read and show books data
+    cout << "\n>>>>>>>>>> Books Data Stored In File <<<<<<<<<<<<<<";
+    fetchAndShowBookData();
+
+    cout << endl; // Add new line
+    cin.ignore();
+    return 0;
+}
+// // Main Function End