What are some examples of using std::map in C++?

Can you give me some examples of using std::map in C++?

Sure! std::map is a sorted associative container that contains key-value pairs. Here's a simple example:

#include <iostream>
#include <map>

int main() {
    std::map<int, std::string> myMap;
    myMap[1] = "One";
    myMap[2] = "Two";
    myMap[3] = "Three";

    for (const auto& pair : myMap) {
        std::cout << pair.first << " : " << pair.second << std::endl;
    }
    return 0;
}

What happens if I try to insert a duplicate key?

If you insert a duplicate key, std::map will not allow it. Instead, it will overwrite the existing value associated with that key. For example:

myMap[2] = "Two Updated";

Can I iterate over the map in reverse order?

Yes, you can iterate in reverse order using reverse iterators. Here's how:

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

What are the advantages of using std::map over std::unordered_map?

The main advantage of std::map is that it maintains the order of elements based on the keys, while std::unordered_map does not. This can be useful when you need sorted data.