In computer science, a data structure is a particular way of storing and organizing data in a computer so that it can be used efficiently.
Different kinds of data structures are suited to different kinds of applications, and some are hightly specialized to specific tasks. For example, B-trees are
particularly well-suited for implementation of databases, while compiler implementations usually use hash tables to look up identifiers.
Data structures are used in almost every program or software system. Data structures provide a means to manage huge amounts of data efficiently, such as large
databases and internet indexing services. Usually, efficient data structures are a key to designing efficient algorithms. Some formal design methods and programming
languages empasize data structures, rather than algorithms, as the key organizing factor in software design.
Basic principles
Data structures are generally based on the ability of a computer to fetch and store data at any place in its memory, specified by an address -- a bit string that can
be itself stored in memory and manipulated by the program. Thus the record and array data structures are based on computing the address of data items with
arithmetic operations; while the linked data structures are based on storing addresses of data items within the structure itself. Many data structures use both
principles, sometimes combined in non-trivial ways (as in XOR linking)
The implementation of a data structure usually requires writing a set of procedures that create and mainpulate instances of that structure. The efficiency of a data
structure cannot be analyzed separately from those operations. This observation motivate the theoretical concept of an abstract data type, a data structure that is
defined indirectly by the operations that may be performed on it, and the mathematical properties of those operations (including their space and time cost).
Common data structures
Common data structures include: array, linked list, hash-table, heap, B-tree, red-black tree, trie, stack, and queue.
Language support
Most Assembly languages and some low-level languages, such as BCPL, generally lack support for data structures. Many high-level programming languages, and some
higher-level assembly languages, such as MASM, on the other hand, have special syntax or other built-in support for certain data structures, such as vectors (one-
dimensional arrays) in the C language and multi-dimensional arrays in Pascal.
Most programming languages feature some sorts of library mechanish that allows data structure implementations to be reused by different programs. Modern languages
usually come with standard libraries that implement the most common data structures. Example are the C++ Standard Template Library, the Java Collections Framework,
and Microsoft's .NET Framework.
Modern languages also generally support modular programming, the separation between the interface of a library module and its implementation. Some provide opaque
data types that allow clients to hide implementation details. Object-oriented programming languages, such as C++, Java and .NET Framework use classes for this purpose.
Many known data structures have concurrent versions that allow multiple computing threads to access the data structure simultaneously.
