Introduction

A personal diary is a great way to keep track of your thoughts, memories, and experiences.
This simple C++ diary application allows you to write, save, and view daily journal entries.
The program lets you create multiple entries, stores them in a text file, and ensures your diary remains safe and easy to access.

Objective: The goal of this program is to provide users with a simple, efficient way to maintain a digital diary. It allows users to write daily entries, save them with a timestamp, and retrieve them as needed, all through a console-based C++ program.

Code

#include 
#include 
#include 
#include 

using namespace std;

void writeEntry() {
    ofstream diaryFile;
    string entry;
    
    // Open diary file in append mode
    diaryFile.open("diary.txt", ios::app);
    
    if (!diaryFile) {
        cout << "Error opening diary file!" << endl;
        return;
    }

    // Get current date and time
    time_t now = time(0);
    char* dt = ctime(&now);
    
    // Write date and entry to file
    diaryFile << "Date: " << dt;
    cout << "Enter your diary entry (type 'EXIT' to stop writing):" << endl;

    // Get user input for diary entry
    while (true) {
        getline(cin, entry);
        if (entry == "EXIT") break;
        diaryFile << entry << endl;
    }

    diaryFile << "------------------------------------\n\n"; // Separation between entries
    diaryFile.close();
    cout << "Your entry has been saved!" << endl;
}

void readEntries() {
    ifstream diaryFile;
    string line;
    
    diaryFile.open("diary.txt");

    if (!diaryFile) {
        cout << "Diary is empty or file not found!" << endl;
        return;
    }

    cout << "\nDiary Entries:\n";
    while (getline(diaryFile, line)) {
        cout << line << endl;
    }

    diaryFile.close();
}

int main() {
    int choice;

    while (true) {
        cout << "\nC++ Diary Application" << endl;
        cout << "1. Write a new entry" << endl;
        cout << "2. Read previous entries" << endl;
        cout << "3. Exit" << endl;
        cout << "Enter your choice: "; cin >> choice;
        cin.ignore(); // To clear the newline character from input buffer
        
        if (choice == 1) {
            writeEntry();
        } else if (choice == 2) {
            readEntries();
        } else if (choice == 3) {
            cout << "Exiting the program. Have a nice day!" << endl;
            break;
        } else {
            cout << "Invalid choice. Please try again." << endl;
        }
    }

    return 0;
}

Program Structure and Explanation

This diary application is a simple console-based C++ program that offers two main functionalities: writing new diary entries and reading previous ones.

• writeEntry(): This function opens the “diary.txt” file in append mode, allowing the user to add new entries. It adds a timestamp with the current date and time before each entry and stores it in the file.
• readEntries(): This function opens the “diary.txt” file in read mode and displays all the saved entries line by line.
• main(): The main function provides a simple menu with three options: to write a new entry, read previous entries, or exit the program. The user input determines which function is called.

How to Run the Program

1. Ensure you have a C++ compiler installed (e.g., GCC or Visual Studio).
2. Copy the code provided above into a file named diary.cpp.
3. Open your terminal or command prompt, navigate to the directory where the file is located, and compile the program using the command: g++ diary.cpp -o diary.
4. Run the program using the command: ./diary on Linux/Mac or diary.exe on Windows.
5. Follow the on-screen menu to write or read diary entries.