c++ - c++向量多个值

Question

我是c++新手，但是有半年Java se/ee7的工作经验。

我想知道如何将 3 个值放入vector<string> 示例中：vector<string, string, string>或者只是vector<string, string> 为了避免使用 3 个向量。

vector<string> questions;
vector<string> answers;
vector<string> right_answer;

questions.push_back("Who is the manufacturer of Mustang?");
answers.push_back("1. Porche\n2. Ford \n3. Toyota");
right_answer.push_back("2");

questions.push_back("Who is the manufacturer of Corvette?");
answers.push_back("1. Porche\n2. Ford \n3. Toyota \n4. Chevrolette");
right_answer.push_back("4");


for (int i = 0; i < questions.size(); i++) {
    println(questions[i]);
    println(answers[i]);

    if (readInput() == right_answer[i]) {
        println("Good Answer.");
    } else {
        println("You lost. Do you want to retry? y/n");
        if(readInput() == "n"){
            break;
        }else{
            i--;
        }
    }
}

questions[i][0] questions[i][1] questions[i][3]如果可能的话，我想使用类似的东西。

Answer 1

您可以在以下位置拥有struct并存储它的对象vector：

struct question
{
    std::string title;
    std::string choices;
    std::string answer;
};

// ...

question q = {"This is a question", "Choice a\nChoice b", "Choice a"};
std::vector<question> questions;
questions.push_back(q);

然后你会使用questions[0].titleorquestions[0].answer等​​。

Answer 2

为什么没有这样的结构：

struct question_data {
    std::string question;
    std::string answers; // this should probably be a vector<string>
    std::string correct_answer;
};

接着：

std::vector<question_data> questions;
...
for (int i = 0; i < questions.size(); i++) { // I would personally use iterator
    println(questions[i].question);
    println(questions[i].answers);

    if (readInput() == questions[i].correct_answer) ...
}

Answer 3

你可以在现代 C++ 中做你想做的事。

您可以使用如下元组：

std::vector<std::tuple<std::string, std::string>> vec;
std::tuple<std::string, std::string> some_tuple;
some_tuple = std::make_tuple("some", "strings");
vec.push_back(some_tuple);

您可以使用 std::tie 稍后阅读它。