hashmap c++

#include <iostream>
#include <unordered_map>

int main() {
    // Step 1: Declare an unordered_map with key-value pairs of type int and string
    std::unordered_map<int, std::string> myHashMap;

    // Step 2: Insert key-value pairs into the unordered_map
    myHashMap.insert({1, "One"});
    myHashMap.insert({2, "Two"});
    myHashMap.insert({3, "Three"});

    // Step 3: Access elements using keys
    std::cout << "Value at key 2: " << myHashMap[2] << std::endl;

    // Step 4: Check if a key exists in the unordered_map
    if (myHashMap.find(3) != myHashMap.end()) {
        std::cout << "Key 3 exists in the unordered_map" << std::endl;
    }

    // Step 5: Update the value associated with a key
    myHashMap[2] = "New Two";

    // Step 6: Iterate through the unordered_map
    std::cout << "Iterating through the unordered_map:" << std::endl;
    for (const auto& pair : myHashMap) {
        std::cout << pair.first << ": " << pair.second << std::endl;
    }

    // Step 7: Remove an element by key
    myHashMap.erase(1);

    // Step 8: Check if the unordered_map is empty
    if (myHashMap.empty()) {
        std::cout << "The unordered_map is empty" << std::endl;
    } else {
        std::cout << "The unordered_map is not empty" << std::endl;
    }

    // Step 9: Get the size of the unordered_map
    std::cout << "Size of the unordered_map: " << myHashMap.size() << std::endl;

    return 0;
}