Polymorphism (computer science)

Not to be confused with Polymorphic code.
Polymorphism
Ad hoc polymorphism
Parametric polymorphism
Subtyping

In programming language theory and type theory, polymorphism is the use of one symbol to represent multiple different types.[1]

In object-oriented programming, polymorphism is the provision of one interface to entities of different data types.[2] The concept is borrowed from a principle in biology where an organism or species can have many different forms or stages.[3]

The most commonly recognized major forms of polymorphism are:

  • Ad hoc polymorphism: defines a common interface for an arbitrary set of individually specified types.
  • Parametric polymorphism: not specifying concrete types and instead use abstract symbols that can substitute for any type.
  • Subtyping (also called subtype polymorphism or inclusion polymorphism): when a name denotes instances of many different classes related by some common superclass.[4]
  1. ^ Cardelli, Luca; Wegner, Peter (December 1985). "On understanding types, data abstraction, and polymorphism" (PDF). ACM Computing Surveys. 17 (4): 471–523. CiteSeerX 10.1.1.117.695. doi:10.1145/6041.6042. S2CID 2921816.: "Polymorphic types are types whose operations are applicable to values of more than one type."
  2. ^ Stroustrup, Bjarne (February 19, 2007). "Bjarne Stroustrup's C++ Glossary". polymorphism – providing a single interface to entities of different types.
  3. ^ "Polymorphism". The Java Tutorials: Learning the Java Language: Interfaces and Inheritance. Oracle. Retrieved 2021-09-08.
  4. ^ Conallen, J.; Engle, M.; Houston, K.; Maksimchuk, R.; Young, B.; Booch, G. (2007). Object-Oriented Analysis and Design with Applications (3rd ed.). Pearson Education. ISBN 9780132797443.