Containers in C++ STL Last Updated : 03 Mar, 2025 Summarize Comments Improve Suggest changes Share Like Article Like Report Standard Template Library (STL) provides the built-in implementation of commonly used data structures known as containers. A container is a holder object that stores a collection of other objects (its elements). They are implemented as class templates, which allows great flexibility in the data types supported.A container manages the storage space for its elements and provides member functions for easy access to useful operations.Types of STL ContainersSTL containers are divided into the following categories:Sequence ContainersAssociative ContainersUnordered ContainersContainer Adapters1. Sequence ContainersSequence containers implement linear data structures in which the elements can be accessed sequentially. Following are the sequence containers in C++ STL:Container NameDescriptionArrayContainer that wraps over fixed size static array.VectorAutomatically resizable dynamic array.DequeDynamic array of fixed-size arrays that allows fast insertions and deletions at both ends.ListImplementation of Doubly Linked List data structure.Forward ListImplementation of Singly Linked List data structure.2. Associative ContainersAssociative containers store data in some sorted order. It provides fast search, insert and delete in O(log n) time by using balanced trees like Red Black Trees. Container NameDescriptionSetCollection of unique elements sorted on the basis of their values.MapCollection of key-value pairs sorted on the basis of the keys where no two pairs have same keys.MultisetCollection of elements sorted on the basis of their values but allows multiple copies of values.MultimapCollection of key-value pairs sorted on the basis of the keys where multiple pairs can have same keys.3. Unordered Associative ContainersUnordered associative containers implement unsorted hashed data structures that can be quickly searched (O(1) amortized, O(n) worst-case complexity).Container NameDescriptionUnordered SetCollection of unique elements hashed by their values.Unordered MapCollection of key-value pairs that are hashed by their keys where no two pairs have same keys.Unordered MultisetCollection of elements hashed by their values and allows multiple copies of values.Unordered MultimapCollection of key-value pairs that are hashed by their keys where multiple pairs can have same keys.4. Container AdaptersContainer adapters provide a different interface for other containers. They adapt the behavior of underlying containers to fit specific use cases.Container NameDescriptionStackAdapts a container to provide stack (LIFO) data structure.QueueAdapts a container to provide queue (FIFO) data structure.Priority QueueAdapts a container to provide heap data structure.To master C++ Standard Template Library (STL) in the most efficient and effective way, do check out this C++ STL Online Course by GeeksforGeeks. The course covers the basics of C++ and in-depth explanations to all C++ STL containers, iterators, etc along with video explanations of a few problems. Also, you'll learn to use STL inbuilt classes and functions in order to implement some of the complex data structures and perform operations on them conveniently. Comment More infoAdvertise with us Next Article Iterators in C++ STL A ayushmaan bansal Follow Improve Article Tags : Misc C++ STL Practice Tags : CPPMiscSTL Similar Reads C++ Tutorial | Learn C++ Programming C++ is a popular programming language that was developed as an extension of the C programming language to include OOPs programming paradigm. Since then, it has become foundation of many modern technologies like game engines, web browsers, operating systems, financial systems, etc.Features of C++Why 5 min read Introduction to c++Difference between C and C++C++ is often viewed as a superset of C. 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