This article is about the computer programming concept. For the mathematical concept, see Equivalence class and Invariant (mathematics).
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In computer programming, specifically object-oriented programming, a class invariant (or type invariant) is an invariant used for constraining objects of a class. Methods of the class should preserve the invariant. The class invariant constrains the state stored in the object.
Class invariants are established during construction and constantly maintained between calls to public methods. Code within functions may break invariants as long as the invariants are restored before a public function ends. With concurrency, maintaining the invariant in methods typically requires a critical section to be established by locking the state using a mutex.
An object invariant, or representation invariant, is a computer programming construct consisting of a set of invariant properties that remain uncompromised regardless of the state of the object. This ensures that the object will always meet predefined conditions, and that methods may, therefore, always reference the object without the risk of making inaccurate presumptions. Defining class invariants can help programmers and testers to catch more bugs during software testing.
a classinvariant (or type invariant) is an invariant used for constraining objects of a class. Methods of the class should preserve the invariant. The...
Look up invariance, invariant, or invariants in Wiktionary, the free dictionary. Invariant and invariance may refer to: Invariant (computer science),...
then f {\displaystyle f} is said to be classinvariant under ∼ , {\displaystyle \,\sim \,,} or simply invariant under ∼ . {\displaystyle \,\sim .} This...
describe a particular language behavior. In RAII, holding a resource is a classinvariant, and is tied to object lifetime. Resource allocation (or acquisition)...
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(such as those that would be loaded onto class I MHC). The invariant chain also facilitates the export of class II MHC from the ER to the Golgi apparatus...
"invariant". More formally, a graph property is a class of graphs with the property that any two isomorphic graphs either both belong to the class, or...
morphism for ∼ , {\displaystyle \,\sim ,} a classinvariant under ∼ , {\displaystyle \,\sim ,} or simply invariant under ∼ . {\displaystyle \,\sim .} This...
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symmetric Holomorphic function on the complex upper half-plane. It is invariant under the fractional linear action of the congruence group Γ(2), and generates...
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In mathematics, geometric invariant theory (or GIT) is a method for constructing quotients by group actions in algebraic geometry, used to construct moduli...
periodic table of topological invariants is an application of topology to physics. It indicates the group of topological invariant for topological insulators...
In mathematics, an invariant subspace of a linear mapping T : V → V i.e. from some vector space V to itself, is a subspace W of V that is preserved by...
In geometry, the Dehn invariant is a value used to determine whether one polyhedron can be cut into pieces and reassembled ("dissected") into another...
scale-invariant theories. The set of different microscopic theories described by the same scale-invariant theory is known as a universality class. Other...
HLA class II histocompatibility antigen gamma chain also known as HLA-DR antigens-associated invariant chain or CD74 (Cluster of Differentiation 74), is...
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In mathematics, the Arf invariant of a nonsingular quadratic form over a field of characteristic 2 was defined by Turkish mathematician Cahit Arf (1941)...
analysis, since they can be used to derive invariants with respect to specific transformation classes. The term invariant moments is often abused in this context...