如何在一个向量中存储多个值？

Question

我是 C++ 新手，但有半年 Java SE/EE7 工作经验。

我想知道如何将 3 个值放入

vector<string>

。
例如：

vector<string, string, string>

或只是

vector<string, string>

以避免使用 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--;
        }
    }
}

如果可能的话，我想使用

questions[i][0]

、

questions[i][1]

、

questions[i][3]

之类的东西。

Answer 1

您可以拥有一个

struct

并将其对象存储在

vector

中：

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].title

或

questions[0].answer

等

Answer 2

为什么不采用如下结构：

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

然后：

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

你可以用现代 C++ 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。