Chapter 11C++ Tutorial~1 min read

File Handling in C++

Files — Read/Write करणे

C++ मध्ये file handling साठी fstream header वापरतात. ofstream — write, ifstream — read, fstream — both. C च्या fopen/fclose पेक्षा more object-oriented approach.

File Write करणे — ofstream

Write to file

cpp

#include <iostream>
#include <fstream>
#include <string>
using namespace std;

int main() {
    // ofstream — output file stream
    ofstream outFile("notes.txt");

    // File उघडली का? check करा
    if (!outFile.is_open()) {
        cout << "File उघडता आली नाही!" << endl;
        return 1;
    }

    // File मध्ये लिहिणे — cout सारखेच!
    outFile << "नमस्कार!" << endl;
    outFile << "हे C++ File Handling चे notes आहेत." << endl;
    outFile << "आज STL शिकलो." << endl;

    outFile.close();  // File बंद करणे
    cout << "File successfully लिहिली! ✅" << endl;

    // Append mode — शेवटी add करणे
    ofstream appendFile("notes.txt", ios::app);
    appendFile << "Extra line appended." << endl;
    appendFile.close();

    return 0;
}

File Read करणे — ifstream

Read from file

cpp

#include <iostream>
#include <fstream>
#include <string>
using namespace std;

int main() {
    ifstream inFile("notes.txt");

    if (!inFile.is_open()) {
        cout << "File सापडली नाही!" << endl;
        return 1;
    }

    // Line by line वाचणे
    string line;
    while (getline(inFile, line)) {
        cout << line << endl;
    }

    inFile.close();

    // Word by word वाचणे
    ifstream f2("data.txt");
    string word;
    while (f2 >> word) {
        cout << word << " ";
    }
    f2.close();

    return 0;
}

fstream — Read + Write दोन्ही

Student data save/load

cpp

#include <iostream>
#include <fstream>
#include <string>
using namespace std;

struct Student {
    string name;
    int marks;
};

int main() {
    // Write students
    ofstream fw("students.txt");
    Student students[] = {{"Rahul", 85}, {"Priya", 92}, {"Amit", 78}};

    for (auto &s : students) {
        fw << s.name << " " << s.marks << endl;
    }
    fw.close();

    // Read back
    ifstream fr("students.txt");
    string name;
    int marks;

    cout << "Students:" << endl;
    while (fr >> name >> marks) {
        cout << "  " << name << ": " << marks
             << (marks >= 40 ? " Pass ✅" : " Fail ❌") << endl;
    }
    fr.close();

    return 0;
}

💡

C++ file streams automatically close होतात जेव्हा object scope च्या बाहेर जातो (RAII). तरीही explicitly close() call करणे good practice आहे — data flush होतो.

✅ Key Points — लक्षात ठेवा

▸ofstream — write (creates/overwrites)
▸ifstream — read
▸fstream — read + write दोन्ही
▸ios::app — append mode
▸getline(file, str) — full line read

0/11 chapters पूर्ण

मागे — Previous

STL — Standard Template Library

अभिनंदन! 🎉

Tutorial Complete!