How to iterate through a map in C++ and delete specific…

In C++, you can use iterators to iterate through a map and delete specific elements. The specific steps are as follows:

1. car

for (auto it = myMap.begin(); it != myMap.end();)
{
    // 遍历的代码
}

1. Delete or remove

if (条件满足)
{
    myMap.erase(it++); // 先用后加，避免迭代器失效
}
else
{
    ++it;
}

Here is the complete sample code:

#include <iostream>
#include <map>

int main()
{
    std::map<int, std::string> myMap;
    myMap[1] = "one";
    myMap[2] = "two";
    myMap[3] = "three";
    myMap[4] = "four";
    myMap[5] = "five";

    // 遍历并删除特定元素
    for (auto it = myMap.begin(); it != myMap.end();)
    {
        if (it->first == 3)
        {
            myMap.erase(it++); // 先用后加，避免迭代器失效
        }
        else
        {
            ++it;
        }
    }

    // 输出结果
    for (const auto& pair : myMap)
    {
        std::cout << pair.first << ": " << pair.second << std::endl;
    }

    return 0;
}

When running the above code, the output will be:

1: one
2: two
4: four
5: five

Element 3 has been successfully removed.