dynamic_dispatch

Dynamic Dispatch

TLDR: Dynamic dispatch is a runtime mechanism in object-oriented programming that determines which method implementation to execute based on the actual type of an object, rather than its reference type. This feature supports polymorphism, allowing a single interface or method call to interact with multiple class implementations dynamically. Dynamic dispatch is foundational in languages like Java and CPP for creating extensible and flexible designs.

In Java, dynamic dispatch occurs when a method is overridden in a subclass, and the method call is resolved at runtime using the actual object type. For instance, a reference of type `Animal` pointing to a `Dog` object will invoke the `bark()` method specific to the `Dog` class. This method resolution process leverages a virtual method table (vtable) or similar data structures to dynamically bind the method call to the correct implementation. Dynamic dispatch is crucial for achieving runtime polymorphism.

The benefits of dynamic dispatch include support for extensibility and adherence to the open-closed principle in software design, allowing new class implementations without modifying existing code. It underpins frameworks and design patterns such as the strategy pattern, enabling context-based behavior selection. While dynamic dispatch introduces a small runtime performance overhead due to method resolution, its role in modular, reusable, and adaptable systems makes it indispensable in modern software development.