How Do OOP, Structs, and Interfaces Differ in Go?

Go does support many object-oriented ideas; it simply takes a different approach from languages such as Java or C#. OOP does not require classes or inheritance. Encapsulation, attaching behavior to data, abstraction, and polymorphism can all be implemented with Go structs, methods, and interfaces. Go usually favors composition and implicit interface satisfaction instead of class hierarchies.

It’s better to treat structs, interfaces, classes, and functions as tools, and procedural, functional, or object-oriented programming as ways of using those tools. A language can support several styles at once. Don’t worry too much about deciding whether Go is officially OOP; focus on learning how structs hold state, methods provide behavior, and interfaces let code depend on capabilities instead of concrete types.

OOP is a programming paradigm, while structs and interfaces are language features. A struct generally groups data, although in Go you can attach methods to it. An interface defines behavior that a type must provide, which supports abstraction and polymorphism. You can combine these features to write object-oriented-style code without using traditional classes or inheritance.

The exact meaning of OOP varies between languages and over time. In the traditional view, it often means classes, inheritance, access control, and methods. In a broader and more useful view, it means organizing software around objects or components that hide their internal state and communicate through defined behavior. Go provides several of those tools, but encourages simpler composition rather than deep inheritance trees.

Think of an interface as a contract: it describes methods that a type can provide, but you normally don’t create an interface value as a concrete object. A struct is an actual type that can be instantiated and can have fields and methods. Any struct whose methods match an interface can be used wherever that interface is expected. For example, an interface with a Serialize method could be implemented by several unrelated structs, allowing the same code to work with all of them.