读取文本文件以C ++结尾

Question

我有这个功能，应该读取到文本文件的末尾，以检索数据并将数据存储在某些变量中。

名字-姓氏-国籍-客人-费用-房间＃

dd dd dd 2 350102   RIC Thing美国2 350104

然后，我使用另一个功能来尝试修改数据。您可以看到变量在哪里有数据，但是当我尝试比较数据时会说找不到该数据。

发现104

请输入您要更改的房间号：104

名字-姓氏-国籍-客人-房间＃

这两个被打印出来，所以我可以看到检索到的内容 102 104

RIC Thing USA 2350104

但找不到102。

请输入您要更改的房号：102

名字-姓氏-国籍-客人-房间＃

这两个被打印出来，所以我可以看到检索到的内容 102 104

抱歉...找不到匹配的内容。

请确保已预订房间号，然后才能对其进行修改。

void HotelRoom::modifyresroom()
{
    int occup;
    string roomtochange;
    string guestroomdb;
    int newaccupancy;
    double newcost;
    char savinf;
    string fname, lname, nationality;
    string checkaddroom;
    ifstream getdatafromaddroom; // creation of the ifstream object
    getdatafromaddroom.open("reserveroom.out");

    cout << "Please enter the room number you would like to make the changes to : ";
    cin >> roomtochange;

    cout << endl;

    if (getdatafromaddroom.fail()) // if statement used for error
    // checking
    {
        cout << "Could not open file" << endl; // message that will be
    }
    cout << "First Name" << '-' << "Last Name" << '-' << "Nationality" << '-' << "Guest(s)" << '-' << "Room #" << endl;
    cout << "-------------------------------------------------------" << endl;

    while (!getdatafromaddroom.eof()) {
        getdatafromaddroom >> fname >> lname >> nationality >> occup >> cost >> guestroomdb;
        if (getdatafromaddroom.eof()) {
            break;
        }
        cout << guestroomdb << endl;
    }
    //if statement begin by error checking
    if (roomtochange != guestroomdb) {

        cout << "SORRY...NO MATCH FOUND." << endl;
        //cout << setw(5) << fname << ' ' << setw(10) << lname << ' ' << setw(10) <<nationality << ' ' << setw(10) << occup<< ' ' << setw(9) << cost << ' ' << setw(9) << guestroomdb <<endl;
        char backtomod;
        cout << endl;
        cout << "Please ensure that the room number typed was  was booked before it can be modified." << endl;
        cout << endl;
        cout << "1 - Enter another room number, 2 - Back to the mail menu : ";
        cin >> backtomod;

        //switch block used to allow the user to reenter the room number or go back to the mail menu
        switch (backtomod) {
        case '1':
            HotelRoom::modifyaddromm();
            break;
        case '2':
            HotelRoom::hotelmenu();
            break;
        default:
            cout << endl;
            cout << "(--" << backtomod << "--)"
                 << " wasn't a valid selection. you will now be directed to the main menu.";
            system("Pause");
            cout << endl;
            HotelRoom::hotelmenu();
            break;
        }
    }
    else {

        // if room number is found t will be printed out below

        cout << setw(5) << fname << ' ' << setw(10) << lname << ' ' << setw(10) << nationality << ' ' << setw(10) << occup << ' ' << setw(9) << cost << ' ' << setw(9) << guestroomdb << endl;
    }

    cout << "How many person should be in the new room? : ";
    cin >> newaccupancy;
    newcost = newaccupancy * HotelRoom::getdailyrate();
    cout << endl;
    cout << "[y] to save : ";
    cin >> savinf;

    cout << fname << ' ' << lname << ' ' << nationality << ' ' << newaccupancy << ' ' << newcost << ' ' << guestroomdb << endl;
    if (savinf == 'y' || savinf == 'Y') {
        ofstream editrecord;
        editrecord.open("reserveroom.out", ios::app);
        editrecord << fname << ' ' << lname << ' ' << nationality << ' ' << newaccupancy << ' ' << newcost << ' ' << guestroomdb << endl;
        editrecord.close();
        getdatafromaddroom.close();
        hotelmenu();
    }
    else {
        cout << "The changes made weren't saved.";
        system("Pause");
        hotelmenu();
    }
    //}
}

Answer 1

bool found = false;
while (getdatafromaddroom >> fname >> lname >> nationality >> occup >> cost >> guestroomdb) {
    if (guestroomdb == roomtochange) {  // stop when you found the
        found = true;                   // record you are interested in
        break;
    }
}

if (!found) {  // found is still false? No such record in the file.
    // handle error