How does std::unordered_map work in C++11?

Can you explain how std::unordered_map works in C++11?

Sure! std::unordered_map is a hash table-based container that stores key-value pairs. It allows for fast retrieval of values based on their keys.

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

The main advantage is performance. std::unordered_map offers average constant time complexity for lookups, while std::map has logarithmic time complexity due to its tree structure.

Are there any specific use cases where std::unordered_map is preferred?

Yes, it's preferred when you need fast access to elements and don't require the elements to be sorted. It's great for implementing caches or frequency counters.

How do I iterate over the elements in an std::unordered_map?

You can use a range-based for loop or an iterator. For example: for (const auto& pair : myMap) { /* access pair.first and pair.second */ }.