如何打印出 C++ 地图值?

2021-12-11 00:00:00 dictionary for-loop printing c++ std-pair

我有一个像这样的 map:

map<string, pair<string,string> > myMap;

我已经使用以下方法将一些数据插入到我的地图中:

And I've inserted some data into my map using:

myMap.insert(make_pair(first_name, make_pair(middle_name, last_name)));

我现在如何打印地图中的所有数据?

How can I now print out all the data in my map?

推荐答案

for(map<string, pair<string,string> >::const_iterator it = myMap.begin();
    it != myMap.end(); ++it)
{
    std::cout << it->first << " " << it->second.first << " " << it->second.second << "
";
}

在C++11中，你不需要拼出map;>::const_iterator.您可以使用 auto

In C++11, you don't need to spell out map<string, pair<string,string> >::const_iterator. You can use auto

for(auto it = myMap.cbegin(); it != myMap.cend(); ++it)
{
    std::cout << it->first << " " << it->second.first << " " << it->second.second << "
";
}

注意 cbegin() 和 cend() 函数的使用.

Note the use of cbegin() and cend() functions.

更简单的是，您可以使用基于范围的 for 循环:

Easier still, you can use the range-based for loop:

for(const auto& elem : myMap)
{
   std::cout << elem.first << " " << elem.second.first << " " << elem.second.second << "
";
}

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