how to do simple inheritance in go

Last Updated : 22 Jun, 2020

Output:

Universe is: MCU
Universe is: DC

Suggestion : 2

Let's first create the author struct.

package main

import(
   "fmt"
)

type author struct {
   firstName string
   lastName string
   bio string
}

func(a author) fullName() string {
   return fmt.Sprintf("%s %s", a.firstName, a.lastName)
}

The next step would be to create the blogPost struct.

type blogPost struct {
   title string
   content string
   author
}

func(b blogPost) details() {
   fmt.Println("Title: ", b.title)
   fmt.Println("Content: ", b.content)
   fmt.Println("Author: ", b.author.fullName())
   fmt.Println("Bio: ", b.author.bio)
}

Whenever one struct field is embedded in another, Go gives us the option to access the embedded fields as if they were part of the outer struct. This means that p.author.fullName() in line no. 11 of the above code can be replaced with p.fullName(). Hence the details() method can be rewritten as below,

func(p blogPost) details() {
   fmt.Println("Title: ", p.title)
   fmt.Println("Content: ", p.content)
   fmt.Println("Author: ", p.fullName())
   fmt.Println("Bio: ", p.bio)
}

The main function of the program above creates a new author in line no. 31. A new post is created in line no. 36 by embedding author1. This program prints,

Title: Inheritance in Go
Content: Go supports composition instead of inheritance
Author: Naveen Ramanathan
Bio: Golang Enthusiast

Let's define the website struct first. Please add the following code above the main function of the existing program and run it.

type website struct {
   [] blogPost
}
func(w website) contents() {
   fmt.Println("Contents of Website\n")
   for _, v: = range w.blogPosts {
      v.details()
      fmt.Println()
   }
}

Suggestion : 3

Go doesn’t have inheritance – instead composition, embedding and interfaces support code reuse and polymorphism.,Further down the road your project might have grown to include more animals. At this point you can introduce polymorphism and dynamic dispatch using interfaces.,Object-oriented programming with inheritance,Inheritance in traditional object-oriented languages offers three features in one. When a Dog inherits from an Animal

If a Dog needs some or all of the functionality of an Animal, simply use composition.

type Animal struct {
   // …
}

type Dog struct {
   beast Animal
   // …
}

If the Dog class inherits the exact behavior of an Animal, this approach can result in some tedious coding.

type Animal struct {
   // …
}

func(a * Animal) Eat() {
   …}
func(a * Animal) Sleep() {
   …}
func(a * Animal) Breed() {
   …}

type Dog struct {
   beast Animal
   // …
}

func(a * Dog) Eat() {
   a.beast.Eat()
}
func(a * Dog) Sleep() {
   a.beast.Sleep()
}
func(a * Dog) Breed() {
   a.beast.Breed()
}

Go uses embedding for situations like this. The declaration of the Dog struct and it’s three methods can be reduced to:

type Dog struct {
   Animal
   // …
}