What are interfaces in Go and how do they work?

What are interfaces in Go and how do they work?

Interfaces in Go are types that specify a contract of methods. A type implements an interface by implementing its methods.

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 method Speak, and Dog implements this interface.

How do I use interfaces to achieve polymorphism in Go?

You can achieve polymorphism by using interfaces as function parameters. For example:

func MakeSound(a Animal) {
    fmt.Println(a.Speak())
}

This function can accept any type that implements the Animal interface.

What are some common use cases for interfaces in Go?

Common use cases include defining behaviors for different types, creating mock objects for testing, and enabling code reuse.