interfaceEx.go

package codesnippets

// interface example

import (
	"fmt"
)

type Node interface {
	SetValue(v int)
	GetValue() int
}

type SLLNode struct {
	next  *SLLNode
	value int
}

func (sNode *SLLNode) SetValue(v int) {
	sNode.value = v
}

func (sNode *SLLNode) GetValue() int {
	return sNode.value
}

func NewSLLNode() *SLLNode {
	return new(SLLNode)
}

type PowerNode struct {
	next  *PowerNode
	value int
}

func (sNode *PowerNode) SetValue(v int) {
	sNode.value = v * 10
}

func (sNode *PowerNode) GetValue() int {
	return sNode.value
}

func NewPowerNode() *PowerNode {
	return new(PowerNode)
}

func interfaceEx() {
	var node Node
	node = NewSLLNode()
	node.SetValue(4)
	fmt.Println("Node is of value ", node.GetValue())

	node = NewPowerNode()
	node.SetValue(5)
	fmt.Println("PowerNode is of value ", node.GetValue())

	// node.(TYPE) verifies if implements this interface
	if n, ok := node.(*PowerNode); ok {
		fmt.Println(n.value)
	}
}