What are interfaces in Go and how do I use them?

What are interfaces in Go and how do I use them?

Interfaces in Go are types that specify a contract by defining methods. Any type that implements those methods satisfies the interface.

Can you give me an example of an interface in Go?

Sure! Here's a simple example:

type Animal interface {
    Speak() string
}

type Dog struct {}

func (d Dog) Speak() string {
    return "Woof!"
}

In this example, Animal is an interface with a Speak method, and Dog implements that method.

How do I implement multiple interfaces in a single struct?

You can implement multiple interfaces by defining all the required methods in your struct. For example:

type Flyer interface {
    Fly() string
}

type Swimmer interface {
    Swim() string
}

type Duck struct {}

func (d Duck) Fly() string {
    return "Flapping wings!"
}

func (d Duck) Swim() string {
    return "Paddling in water!"
}

Here, Duck implements both Flyer and Swimmer interfaces.

What are the benefits of using interfaces in Go?

Interfaces promote loose coupling and allow for more flexible code. They enable polymorphism, making it easier to swap implementations without changing the code that uses them.