What are the differences between interfaces and abstract classes in Go?

What are the differences between interfaces and abstract classes in Go?

In Go, interfaces are a way to define behavior, while abstract classes are not a concept in Go. Interfaces allow you to specify methods that must be implemented by any type that satisfies the interface.

Can you give me an example of how to use an interface in Go?

Sure! Here's a simple example:

package main

import "fmt"

type Speaker interface {
    Speak() string
}

type Dog struct {}

type Cat struct {}

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

func (c Cat) Speak() string {
    return "Meow!"
}

func main() {
    var s Speaker
    s = Dog{}
    fmt.Println(s.Speak()) // Outputs: Woof!
    s = Cat{}
    fmt.Println(s.Speak()) // Outputs: Meow!
}

This code defines a Speaker interface and two types, Dog and Cat, that implement the Speak method.

What about abstract classes? How do they differ from interfaces?

Go does not have abstract classes like some other languages. Instead, you can achieve similar functionality using interfaces and struct embedding. Abstract classes typically allow for shared implementation, while interfaces focus on defining behavior without implementation.

Are there any performance differences between using interfaces and concrete types?

Yes, using interfaces can introduce a slight performance overhead due to dynamic dispatch. However, the difference is often negligible unless you're in a performance-critical section of code.