Inheritance in GO using interface

This post describes inheritance using interface. Do visit our Inheritance in Go Complete Guide post for full reference

OOP: Inheritance in GOLANG complete guide

Go supports inheritance by embedding struct or using interface. There are different ways of doing it and each having some limitations. The different ways are:

1. By using embedded struct – The parent struct is embedded in child struct. The limitation is that subtyping is not possible with this approach. You cannot pass the child struct to a function that expects base. Refer this link for more details –Inheritance using struct
2. By using interfaces – Subtyping is possible but the limitation is that one has no way to refer to common properties. Current post describes this approach
3. By using interface + struct – This fixes the limitations of above two approach but one limitation is that overriding methods is not possible. But there is a workaround. Refer to this link for more details – Inheritance using interface + struct

Details:

The child struct implements the methods of a common interface. This approach also solves the problem of subtyping. See below code

package main

import "fmt"

type iBase interface {
	say()
}

type child struct {
	style string
}

func (b *child) say() {
	fmt.Println(b.style)
}

func check(b iBase) {
	b.say()
}

func main() {
	child := &child{
		style: "somestyle",
	}
	child.say()
	check(child)
}

Output:

somestyle
somestyle

Limitation:

This approach has a limitation that it is not possible to refer to common properties as an interface can not have any properties. This problem is solved by the mixed approach of using Struct + Interface.