How is the object-oriented structure implemented in the Go language and how does it differ from the classical one?

In Go, object-oriented structures are implemented through composition and interfaces, rather than classes and inheritance as in traditional OOP.

Main differences:

• Lack of classes: Go does not have classes; instead, it uses structures (struct) that contain fields and methods.
• Composition instead of inheritance: Instead of inheriting from structures, you can include one structure within another, allowing code reuse.
• Interfaces: Interfaces in Go define a set of methods that a structure must implement. Types automatically implement an interface if they have the required methods, without explicit declaration.

Example:

package main
import "fmt"

type Animal interface {
    Speak() string
}

type Dog struct {}

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

type Cat struct {}

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

func main() {
    animals := []Animal{Dog{}, Cat{}}
    for _, a := range animals {
        fmt.Println(a.Speak())
    }
}

Thus, Go offers a simpler and more flexible OOP model based on interfaces and composition, without the complexities of classical inheritance.