type [接口名] interface {
    方法名1(參數(shù)列表) 返回值列表   
    方法名2(參數(shù)列表) 返回值列表
    ...
}

type Isay interface{
  sayHi()
}

//定義接口的實(shí)現(xiàn)類
type Chinese struct{}
//實(shí)現(xiàn)接口
func (_ *Chinese) sayHi() {
  fmt.Println("中國(guó)人說(shuō)嗨")
}

//中國(guó)人
type Chinese struct{}
//美國(guó)人
type Americans struct{}
func (this *Chinese) sayHi()  {
  fmt.Println("中國(guó)人說(shuō)嗨")
}
func (this Americans) sayHi()  {
  fmt.Println("美國(guó)人說(shuō)hi")
}
//調(diào)用
&Chinese{}.sayHi()
Americans{}.sayHi()

interface{}

var v1 interface{} = 1
var v2 interface{} = "abc"
var v3 interface{} = struct{ X int }{1}

func Fprint(w io.Writer, a ...interface{}) (n int, err error)
func Fprintf(w io.Writer, format string, a ...interface{})
func Fprintln(w io.Writer, a ...interface{})
func Print(a ...interface{}) (n int, err error)
func Printf(format string, a ...interface{})
func Println(a ...interface{}) (n int, err error)

//說(shuō)話
type Isay interface{
  sayHi()
}
//工作
type Iwork interface{
  work()
}

//定義一個(gè)接口，組合了上述兩個(gè)接口
type IPersion interface{
  Isay
  Iwork
}

type Chinese struct{}

func (_ Chinese) sayHi() {
  fmt.Println("中國(guó)人說(shuō)中國(guó)話")
}

func (_ Chinese) work() {
	fmt.Println("中國(guó)人在田里工作")
}

//上述接口等價(jià)于：
type IPersion2 interface {
	sayHi()
	work()
}

package main
import "fmt"
//中國(guó)話
type Isay interface {
	sayHi()
}
//工作
type Iwork interface {
	work()
}
//中國(guó)人
type Chinese struct{}
//美國(guó)人
type Americans struct{}
func (this *Chinese) sayHi() {
	fmt.Println("中國(guó)人說(shuō)嗨")
}
func (this Americans) sayHi() {
	fmt.Println("美國(guó)人說(shuō)hi")
}
type IPersion interface {
	Isay
	Iwork
}
func (_ Chinese) work() {
	fmt.Println("中國(guó)人在田里工作")
}
func main() {
	var chinese Isay = &Chinese{}
	chinese.sayHi()
	Americans{}.sayHi()
	//接口組合
	var ipersion IPersion = &Chinese{}
	ipersion.sayHi()
	ipersion.work()
}