In Go, a statically typed programming language, composition is achieved through struct embedding. Struct embedding allows a struct type to include another struct type as one of its fields. This creates a relationship between the two structs where the outer struct can access the fields and methods of the embedded struct as if they were its own.
By using composition, you can combine multiple smaller structs to create more complex structs that fulfill specific behaviors or roles. This approach allows for greater flexibility and avoids the drawbacks associated with deep inheritance hierarchies, such as the diamond problem and tight coupling.
- Flexibility: With composition, you can dynamically change the behavior of a struct by swapping or adding different components. This provides more flexibility than a fixed inheritance hierarchy, where changes to the superclass can impact all its subclasses.
- Code reuse: Composition promotes code reuse by allowing you to create reusable components that can be combined in different ways. This reduces code duplication and makes it easier to maintain and modify code.
- Loose coupling: Composition leads to loose coupling between components. Each component can operate independently, and modifications to one component are less likely to affect others. This promotes better isolation and easier testing.
- Better encapsulation: Composition allows you to control the visibility and accessibility of the embedded struct’s fields and methods. You can choose which fields and methods should be exposed by the outer struct, enhancing encapsulation and hiding unnecessary implementation details.
Reference: