Question

有人可以提供一个在c ++中返回map的函数的实际示例。

我尝试过其他帖子的答案，但我不知道如何申请。

这是我的工作代码：

auto DataArray = jvalue.at(U("data")).as_array();

//Make an associative array or map with key value pair from extracted json data
std::map<int, std::string> staffMap;

// loop through 'data' object
for (int i = 0; i < DataArray.size(); i++)
{
    try
    {
        auto data = DataArray[i];
        auto dataObj = data.as_object();

        int key;
        std::string value;

        // loop through each object of 'data'
        for (auto iterInner = dataObj.cbegin(); iterInner != dataObj.cend(); ++iterInner)
        {
            auto &propertyName = iterInner->first;
            auto &propertyValue = iterInner->second;
            //std::wcout << "Property: " << propertyName << ", Value: " << propertyValue << std::endl;

            if (propertyName == L"_id")
            {
                key = propertyValue.as_integer();
            }
            else if (propertyName == L"name")
            {
                value = conversions::to_utf8string(propertyValue.as_string());
            }
        }

        staffMap.insert(std::make_pair(key, value));
    }
    catch (const std::exception& e)
    {
        std::wcout << e.what() << std::endl;
    }
 }

  // Iterate through map and display in terminal
  std::map<int, std::string>::iterator iter;
  std::wcout << "The list of staffs" << std::endl;
  for (iter = staffMap.begin(); iter != staffMap.end(); iter++)
  std::cout << iter->first << " " << iter->second << " ,";

我想要一个功能：

std::map<int, std::string> staffMap;
std::map<> GetStaffMap()
{
  return staffMap;
}

// Give staffMap a data here

我找不到足够的教程来制作一个在c ++中返回std :: map的函数。希望有人能在这里帮助我。谢谢。

Answer 1

我找不到足够的教程来创建一个在c ++中返回std :: map的函数。希望有人能帮助我

您需要指定确切类型string.words_and_punctuation => ["The", "man's", "hat", ",", "was", "very", "nice", "."] string.words_and_punctuation.select(&:punctuation?) => ["man's", ",", "."]：

std::map<int, std::string>

如果您能够使用C ++ 14，请使用auto替代：

std::map<int, std::string> GetStaffMap()
{
    return staffMap;
}

Answer 2

下面的示例显示了如何在C ++中创建一个返回地图的函数。

<!DOCTYPE html>
<html>
<head>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
  <link rel="stylesheet" type="text/css" href="border.css">
  <link rel="stylesheet" href="https://use.fontawesome.com/releases/v5.0.10/css/all.css" integrity="sha384-+d0P83n9kaQMCwj8F4RJB66tzIwOKmrdb46+porD/OvrJ+37WqIM7UoBtwHO6Nlg" crossorigin="anonymous">
</head>

<body>

  <button class="btn"><i class=" fas fa-shipping-fast fa-inverse"></i></button>
  <button class="btn"><i class=" fas fa-address-card fa-inverse"></i></button>
  <button class="btn"><i class=" fas fa-camera-retro fa-inverse"></i></button>
  <button class="btn"><i class="fas fa-flag fa-inverse"></i></button>
  <button class="btn"></button>

  <script type="text/javascript">
  var buttons = document.getElementsByClassName("btn");

  for (var i = 0; i < buttons.length; i++) {
    document.getElementsByClassName("btn")[i].addEventListener("click", function() {
		if(this.classList.contains("skill_lvl_3"))
		  this.classList.add("skill_lvl_4");
		else if(this.classList.contains("skill_lvl_2"))
		  this.classList.add("skill_lvl_3");
		else if(this.classList.contains("skill_lvl_1"))
		  this.classList.add("skill_lvl_2");
		else if(this.classList.contains("skill_unlocked"))
		  this.classList.add("skill_lvl_1");
		else
		   this.classList.add("skill_unlocked");
    });
  }
  </script>

</body>
</html>

在c ++中返回map的函数

2 个答案: