Containers in C++ STL (Standard Template Library)

A container is a holder object that stores a collection of other objects (its elements). They are implemented as class templates, which allows a great flexibility in the types supported as elements.

The container manages the storage space for its elements and provides member functions to access them, either directly or through iterators (reference objects with similar properties to pointers).

Sequence containers

Sequence containers implement data structures which can be accessed sequentially.

  • array: Static contiguous array (class template)
  • vector: Dynamic contiguous array (class template)
  • deque: Double-ended queue (class template)
  • forward_list: Singly-linked list (class template)
  • list : Doubly-linked list (class template)

Associative containers

Associative containers implement sorted data structures that can be quickly searched (O(log n) complexity).

  • Set: Collection of unique keys, sorted by keys
    (class template)

  • Map: Collection of key-value pairs, sorted by keys, keys are unique (class template).
  • multiset: Collection of keys, sorted by keys (class template)
  • multimap: Collection of key-value pairs, sorted by keys
    (class template)

Unordered associative containers

Unordered associative containers implement unsorted (hashed) data structures that can be quickly searched (O(1) amortized, O(n) worst-case complexity).

Container adaptors

Container adaptors provide a different interface for sequential containers.

  • stack: Adapts a container to provide stack (LIFO data structure) (class template).
  • queue: Adapts a container to provide queue (FIFO data structure) (class template).
  • priority_queue: Adapts a container to provide priority queue (class template).

Flowchart of Adaptive Containers and Unordered Containers

Flowchart of Sequence conatiners and ordered containers

More Useful Links

Attention reader! Don’t stop learning now. Get hold of all the important DSA concepts with the DSA Self Paced Course at a student-friendly price and become industry ready.

My Personal Notes arrow_drop_up

Check out this Author's contributed articles.

If you like GeeksforGeeks and would like to contribute, you can also write an article using or mail your article to See your article appearing on the GeeksforGeeks main page and help other Geeks.

Please Improve this article if you find anything incorrect by clicking on the "Improve Article" button below.

Improved By : AnkurPaul

Article Tags :
Practice Tags :


Please write to us at to report any issue with the above content.