How do I get keys from a std::map in C++11?

How do I get keys from a std::map in C++11?

You can retrieve keys from a std::map by iterating through the map and accessing the key of each element.

Can you show me a code example?

Sure! Here's a simple example:

#include <iostream>
#include <map>

int main() {
    std::map<int, std::string> myMap = {{1, "one"}, {2, "two"}, {3, "three"}};
    for (const auto& pair : myMap) {
        std::cout << pair.first << std::endl; // Accessing the key
    }
    return 0;
}

What if I want to store the keys in a vector?

You can do that by creating a vector and using the push_back method to add each key. Here's how:

#include <vector>
#include <map>

std::vector<int> keys;
for (const auto& pair : myMap) {
    keys.push_back(pair.first);
}