Invariant and invariance may refer to:

Computer science

Invariant (computer science) In mathematics, an invariant is a property of a mathematical object (or a class of mathematical objects) which remains unchanged after operations or transformations of a certain type are applied to the objects. The particular class of object ...

, an expression whose value doesn't change during program execution **

Loop invariant In computer science, a loop invariant is a property of a program loop that is true before (and after) each iteration. It is a logical assertion, sometimes checked within the code by an assertion call. Knowing its invariant(s) is essential in ...

, a property of a program loop that is true before (and after) each iteration * A data type in method overriding that is neither covariant nor contravariant *

Class invariant 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 constr ...

, an invariant used to constrain objects of a class

Physics, mathematics, and statistics

Invariant (mathematics) In mathematics, an invariant is a property of a mathematical object (or a class of mathematical objects) which remains unchanged after operations or transformations of a certain type are applied to the objects. The particular class of object ...

, a property of a mathematical object that is not changed by a specific operation or transformation **

Rotational invariance In mathematics, a function defined on an inner product space is said to have rotational invariance if its value does not change when arbitrary rotations are applied to its argument. Mathematics Functions For example, the function :f(x,y) = ...

, the property of function whose value does not change when arbitrary rotations are applied to its argument **

Scale invariance In physics, mathematics and statistics, scale invariance is a feature of objects or laws that do not change if scales of length, energy, or other variables, are multiplied by a common factor, and thus represent a universality. The technical te ...

, a property of objects or laws that do not change if scales of length, energy, or other variables, are multiplied by a common factor **

Topological invariant In topology and related areas of mathematics, a topological property or topological invariant is a property of a topological space that is invariant under homeomorphisms. Alternatively, a topological property is a proper cla