转换此函数以读取整个文件

Question

我用 C++ 编写了一个测验程序。它正在工作，但文件中的每个问题都有单独的指令块。我需要转换指令块（在 for 之后）以解决所有问题。

文件如下所示

1.WHEN COMPUTER WAS FIRST INVENTIONED?
a.1822
b.1823
c.1834
d.1922

2.WHO kILLED PRESEDENT BENOGIR VUTTO?
a.nawaz shrif
b.pervase
c.non of them
d.political leder

这只是我程序中的一个函数。

void Question::quiz(int &Total)
{
    string line[200];
    string answer;
    string easy[15]={"a","c","a","a","b","c","d","c","a","b","b","c","c","c","a"};

    ifstream fin("questions.txt");
    if(!fin)
    {
        cout<<"Cannot open file\n";
        exit(1);
    }

    cout<<"The first question is\n";
    for(int contor=0;contor<5;contor++)
    {
        getline(fin,line[contor]);
        cout<<line[contor]<<'\n';
    }
    cout<<"Select your answer: ";
    cin >> answer;


    if(answer==easy[0])
    {
        Total+=1;    
    }
    cin.get();     
}

Answer 1

您可以使用 while 循环来读取文件直到行尾。由于每个块恰好包含五行，因此您可以为每行输入输入，直到您获得大于 0 的行大小。因为空白行也将在输入中，您需要忽略它们。

void Question::quiz(int &Total)
{
        string line[200];
        string answer;
        string easy[15]= {"a","c","a","a","b","c","d","c","a","b","b","c","c","c","a"};

        ifstream fin("questions.txt");
        if(!fin)
        {
            cout<<"Cannot open file\n";
            exit(1);
        }
        int cnt=0;
        while(getline(fin,line[0]))
        {
            cout<<line[0]<<endl;
            while(line[0].size()==0)
            {
                getline(fin,line[0]);
                cout<<line[0]<<endl;
            }

            for(int contor=1; contor<5; contor++)
            {
                do
                {
                    getline(fin,line[contor]);
                }
                while(line[contor].size()==0);
                cout<<line[contor]<<'\n';
            }

            cout<<"Select your answer: ";
            cin >> answer;
            if(answer==easy[cnt++])total++;
            line[0]="";
        }
        cout<<total<<endl;
}

Answer 2

这是一个使用对象和向量的方法：

struct quiz_question
{
    auto print_question() -> void
    {
        char prefix[] = { 'a', 'b', 'c', 'd' };
        std::cout << "Question " << question_number << ": " << question << '\n';
        for (auto x = 0; x < possible_answers.size(); x++)
        {
            std::cout << prefix[x] << ". " << possible_answers[x] << '\n';
        }
    }
    auto check_answer(char user_answer) -> bool { return user_answer == answer; }

    std::size_t                  question_number;
    std::string                  question;
    std::array< std::string, 4 > possible_answers;
    char                         answer;
};

int main()
{
    std::vector< quiz_question > questions;
    std::string                  number_of_questions_str;
    std::size_t                  number_of_questions;

    std::ifstream ifs("questions.txt");
    if (!ifs)
    {
        std::cout << "Cannot open questions.txt!\n";
        exit(1);
    }

    // Start loading in questions.
    // Read first line, describes how many questions there are.
    std::getline(ifs, number_of_questions_str);
    ifs.ignore(10000, '\n');   // Ignore a line
    try
    {
        number_of_questions = std::stoul(number_of_questions_str);
    }
    catch (std::invalid_argument &ec)
    {
        std::cout << "Unable to parse questions.txt!\n";
        exit(1);
    }

    // Load each question in.
    for (auto x = 0; x < number_of_questions; x++)
    {
        quiz_question current_question;
        current_question.question_number = x + 1;
        // Read the question line
        std::getline(ifs, current_question.question);

        // Read the possible answers
        for (auto &possible_answer : current_question.possible_answers)
        {
            std::getline(ifs, possible_answer);
        }

        // Read the actual answer
        current_question.answer = ifs.get();
        ifs.ignore(10000, '\n');   // Ignore the rest of that line
        questions.push_back(std::move(current_question));

        ifs.ignore(10000, '\n');   // Ignore a line
    }

    // Now all the questions have been loaded. Lets start the quiz!
    char        answer;
    std::size_t score { 0 };
    std::cout << "Starting the quiz!\n";
    for (auto &question : questions)
    {
        question.print_question();   // Print question and possible answers
        std::cin >> answer;

        if (question.check_answer(answer))
        {
            std::cout << "Correct!\n\n";
            score++;
        }
        else
        {
            std::cout << "Incorrect!\n\n";
        }

        std::cin.clear();               // Clear flags
        std::cin.ignore(10000, '\n');   // Skip to next line
    }
}

我也不得不稍微改变一下你的 questions.txt 格式，如下所述：

问题.txt

2

WHEN COMPUTER WAS FIRST INVENTIONED?
1822
1823
1834
1922
a

WHO KILLED PRESEDENT BENOGIR VUTTO?
nawaz shrif
pervase
non of them
political leder
c

1. 第一行是您的问题总数。
2. 空白行。
3. 问题行
4. 回答A
5. 答案 B
6. 答案 C
7. 回答 D
8. 正确答案
9. 空白行
10. 重复数字 3-9

希望对你有帮助