如何在C++中将文件作为参数传递

How can i pass a file as a parameter in C++?

本文关键字:文件 参数传递 C++      更新时间:2023-10-16

我想做的基本上是写一个函数,它以一个参数作为文件名,如果有多个文件,它只会以文件名作为参数,它应该用一个函数重复这样做。我该怎么做?谢谢

Txt文件如下例如,sorular.txt:

//世界上最拥挤的国家是什么
//中国
//美国
//德国
//澳大利亚
//中国

int main (){
    string array [5];
    string line;
    string answer;
    static int trueCount = 0;
    static int falseCount = 0;
    ifstream file("/Users/User/QuizMaker/Quiz Maker V2/sorular.txt");
    if(file.is_open()){
        cout << "Questions are loading... Please wait.."<<endl<<" ."<<endl<<" ."<<endl<<" ."<<endl;
        while (!file.eof()) {
            for (int i = 0; i<6; i++) {
                getline(file,array[i]);
            }
            for (int a = 0; a<5; a++) {
                  cout << array[a] << endl;
            }
            cin >> answer;
            if(answer == "C" || answer == "c") {
                cout << true;
                trueCount++;
            }
            else falseCount++;
        }
        cout << "You answered "<<trueCount << " questions as true" << endl;
        cout << "You answered "<<falseCount << " questions as false" << endl;
        file.close();
    } else cout << " not ıoen";
    cin.get();
    return 0;
}

首先让我说,array不能容纳元素012345。它只分配了5个元素。


这可能会让你的视野有所开阔,但我认为正确的解决方案是在这里上课。所以我要一起解决这个问题,如果你感兴趣,你可以研究一下我做了什么,如果你不明白,可以在评论中提问。

class foo : public iterator<input_iterator_tag, string> {
    const initializer_list<const char*> _files;
    decltype(_files)::const_iterator _filesIt;
    ifstream _file;
    string _line;
    void get() {
        string array[6];
        auto i = begin(array);
        while (i != end(array) && getline(_file, *i)) {
            advance(i, 1);
        }
        if (i == end(array)) {
            _line = accumulate(cbegin(array), cend(array), string(), [](const auto& a, const auto& b) { return a.empty() ? b : a + 'n' + b; });
        } else if(++_filesIt != cend(_files)) {
            _file.close();
            _file.open(*_filesIt);
            get();
        }
    }
public:
    foo() : _filesIt(cend(_files)) {}
    foo(foo& rhs) : _files(rhs._files), _filesIt(next(cbegin(_files), distance(cbegin(rhs._files), rhs._filesIt))), _line(rhs._line) {
        if (_filesIt != cend(_files)) {
            _file.open(*_filesIt);
            _file.seekg(rhs._file.tellg());
        }
    }
    foo(const initializer_list<const char*>&& files) : _files(files), _filesIt(cbegin(_files)), _file(*_filesIt) { get(); }
    const string& operator*() const { return _line; }
    const foo& operator++() {
        get(); 
        return *this;
    }
    const foo operator++(int) {
        foo result;
        get();
        return result;
    }
    bool operator==(const foo& rhs) { return distance(_filesIt, cend(_files)) == distance(rhs._filesIt, cend(rhs._files)); }
    bool operator!=(const foo& rhs) { return distance(_filesIt, cend(_files)) != distance(rhs._filesIt, cend(rhs._files)); }
};

尽管这门课看起来很难应付,但它极大地简化了你要做的其他事情。有了这个类,你的代码的其余部分将阅读:

auto true_count = 0;
auto false_count = 0;
for_each(foo({"/Users/User/QuizMaker/Quiz Maker V2/sorular.txt", "foo.txt", "bar.txt"}), foo(), [&](const auto& i) {
    string answer;
    cout << i << endl;
    cin >> answer;
    if(answer == "C" || answer == "c") {
        cout << 1;
        true_count++;
    } else {
        false_count++;
    }
});
cout << "You answered "<< trueCount << " questions as true" << endl << "You answered " << falseCount << " questions as false" << endl;