获取C ++ map中的元素索引 [英] Get index of element in C++ map

问题描述

我的C ++应用程序中有一个名为 myMap 的 std :: map ，我希望得到一个元素使用 myMap.find（key）或 myMap [key] 。但是，我还想在地图中获取该元素的索引。

I have a std::map called myMap in my C++ application, and I want to get an element using either myMap.find(key) or myMap[key]. However, I would also like to get the index of that element in the map.

std::map<string, int> myMap;
// Populate myMap with a bunch of items...
myElement = myMap["myKey"];
// Now I need to get the index of myElement in myMap

是否有干净这样做的方法是什么？

Is there a clean way to do that?

谢谢。

推荐答案

A std :: map 实际上没有索引，而是有一个键/值对的迭代器。这类似于索引，因为它表示集合中的排序位置，但它不是数字。要获取键/值对的迭代器，请使用 find 方法

A std::map doesn't really have an index, instead it has an iterator for a key / value pair. This is similar to an index in that it represents a position of sorts in the collection but it is not numeric. To get the iterator of a key / value pair use the find method

std::map<string, int>::iterator it = myMap.find("myKey");

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