superclasses

A superclass is a term used in different domains to describe a higher-level category that other groups inherit from or belong to. In computing, the concept appears most prominently in object-oriented programming.

In object-oriented programming, a superclass (also called a base class or parent class) is a class from which other classes derive attributes and methods. A class that inherits from a superclass is called a subclass (or derived class). Inheritance creates an is-a relationship and supports code reuse, as the subclass automatically acquires the superclass’s fields and behavior. Languages vary in their inheritance models, with single inheritance (one superclass) and multiple inheritance (several superclasses) being supported in different languages. Access to superclass members is often facilitated by a special construct (such as super or base) to call overridden methods or access inherited members. Polymorphism allows code that references the superclass to operate on subclass instances transparently.

Design considerations for superclasses include capturing common behavior and state to minimize duplication, while maintaining clear, maintainable hierarchies. Overly broad or fragile superclass structures can lead to tight coupling and brittleness, so many developers favor composition or interfaces alongside inheritance, and apply the principle of substitutability (objects of a subclass should be usable wherever a superclass is expected).

In biology, a superclass is also used as a taxonomic rank in some classifications, placed above class and below phylum. Its usage is not universal and varies by authority; some schemes employ the rank to group related classes within a phylum, while others omit it altogether.

Overall, superclasses serve to organize related concepts, enabling reuse and abstraction in programming and providing a hierarchical grouping mechanism in taxonomy where applied.