If i input number 2 for std::cin >> menu;, the code after std::cin >> menu; won’t execute.
At first, i think the problem is in the function, but the code haven’t even go to the switch (i have debugged it with std::cout in the switch and after std::cin >> menu;).

After i input 2, it’s just stuck there like loading some massive proccess, while all i do is just take the menu to be the switch parameter.

what is wrong with my code can someone help?

#include <iostream>
#include <fstream>
#include <unistd.h>

struct jadwal {
    std::string Jurusan;
    int Jam;
    int Durasi;
};

void daftarMenu() {
    std::cout << "aplikasi pertemuan" << std::endl;
    std::cout << "menu : " << std::endl;
    std::cout << "[1]. Input" << std::endl;
    std::cout << "[2]. Output" << std::endl;
    std::cout << "[3]. Hasil" << std::endl;
    std::cout << "[4]. Exit" << std::endl;
}

void inputJadwal() {
    int jumlah;
    jadwal jadwal[100];
    std::cout << "Masukkan jumlah jadwal yang ingin ditambahkan : ";
    std::cin >> jumlah;

    std::ofstream file;
    file.open("file1.txt", std::ios::app);
    if(!file) {
        file.open("file1.txt", std::ios::trunc);
    };

    for(int i = 0; i < jumlah; i++) {
        std::cin.ignore();
        std::cout << "Jurusan : ";
        getline(std::cin, jadwal[i].Jurusan);
        file << jadwal[i].Jurusan;

        file << std::endl;

        std::cout << "Jam : ";
        std::cin >> jadwal[i].Jam;
        file << jadwal[i].Jam;

        file << std::endl;

        std::cout << "Durasi : ";
        std::cin >> jadwal[i].Durasi;
        file << jadwal[i].Durasi;

        file << std::endl;
    };

    file.close();

    std::cout << "Data berhasil di input, mengembalikan ke menu utama..." << std::endl;
    sleep(2);
};

void outputJadwal() { 
    jadwal jadwal[100];
    std::ifstream file;
    file.open("file1.txt");
    std::cout << "tes";
    if(!file) {
        std::cout << "Tidak ada jadwal terdaftar" << std::endl;
        sleep(2);
        return;
    };

    std::cout << "tes";
    int index = 0;
    while(!file.eof()) {
        file >> jadwal[index].Jurusan;
        file >> jadwal[index].Jam;
        file >> jadwal[index].Durasi;
        index++;
    }

    int total = index + 1;

    for(int i = 0; i < total; i++) {
        std::cout << "Jurusan : " << jadwal[i].Jurusan;
        std::cout << "Jam " << jadwal[i].Jam;
        std::cout << "Durasi " << jadwal[i].Durasi;
    }

    file.close();
};

void hasilJadwal() {

};

int main() {
    int menu;
    int jumlah;
    
    do{
        //
        daftarMenu();
        std::cout << "Pilih : ";
        std::cin >> menu;
        
        // this code won't execute if i enter number 2 for the menu, but it is okay if i enter 1, 3, 4, 5, or more
        std::cout << "you are choosing menu " << menu;

        switch(menu) {
            case 1:
                inputJadwal();
                break;
            case 2:
                std::cout << "case 2 selected";
                outputJadwal();
                break;
            case 3:
                hasilJadwal();
                break;
            case 4:
                std::cout << "Mengeliminasi program...";
                return 0;
            default:
                std::cout << "Input tidak valid, mengembalikan ke menu utama..." << std::endl;
                sleep(2);
                break;
        }

    }while(true);
    return 0;
}

I have tried this solution from Chat GPT but it doesn’t do anything.

if(std::cin.fail()) {
            std::cerr << "Error: Invalid input. Clearing input buffer and retrying..." << std::endl;
            std::cin.clear(); // Clear the error flags
            std::cin.ignore(std::numeric_limits<std::streamsize>::max(), 'n'); // Discard invalid input
            sleep(2);
            continue; // Retry the loop
        }

        std::cin.ignore(std::numeric_limits<std::streamsize>::max(), 'n');

I personally don’t think there is any problem in my code, atleast in the int main(), because my problem is only in int main();