STL Containers

• Vector
• List
• Deque
• Stack
• Queue
• Priority Queue
• Set
• Map
• Unordered Map

Check if a key is in an unordered_map

// Using find() to access a book's title
auto it = library_catalog.find("book1");
if (it != library_catalog.end())
    std::cout << it->second << std::endl; // Output: "A Tale of Two Cities"
else
    std::cout << "Key not found" << std::endl;

// Using find() to access a nonexistent key
auto it_nonexistent = library_catalog.find("book100");
if (it_nonexistent != library_catalog.end())
    std::cout << it_nonexistent->second << std::endl;
else
    std::cout << "Key not found" << std::endl; // Output: "Key not found"