instantiating

Instantiating is the act of creating a concrete, usable object or element from a general template such as a class, type, or schema. An instance embodies a specific set of values while sharing the structure and behavior defined by its template. The process establishes an identity distinct from the template itself and from other instances.

In object-oriented programming, instantiation typically occurs by constructing an object. A constructor or factory method allocates memory, initializes fields, and returns a reference to the new object. For example, in Java one might write obj = new MyClass(); in Python obj = MyClass(); and in C++ MyClass obj; or MyClass obj(args); Instantiation may be dynamic (at runtime) or static (at compile time, as with some static object declarations). Factories or dependency injection are common patterns that control or defer instantiation.

Generics and templates extend the idea of instantiation. A generic type or template provides a blueprint, and instantiating it with concrete type parameters yields a specific type or class, such as List<String> in Java or std::vector<int> in C++. The resulting instances operate with the behaviors defined by the generic or templated type, but with types or parameters fixed.

Other domains also use the term. In formal logic, instantiation replaces variables with concrete terms to produce a specific instance of a formula. In databases and knowledge representations, an instance refers to a concrete set of data conforming to a schema.

Overall, instantiating connects abstract templates with concrete, usable entities, enabling systems to manage diverse data and objects efficiently.