Go语言接口的用法详解

package main

import (
    "fmt"
    "io"
    "net/Http"
    "os"
)

// init 在main 函数之前调用
func init() {
    if len(os.Args) != 2 {
        fmt.Println("Usage: ./example2 <url>")
        os.Exit(-1)
    }
}

// main 是应用程序的入口
func main() {
    // 从WEB 服务器得到响应
    r, err := http.Get(os.Args[1])
    if err != nil {
        fmt.Println(err)
        return
    }

    // 从Body 复制到Stdout
    io.Copy(os.Stdout, r.Body)
    if err := r.Body.Close(); err != nil {
        fmt.Println(err)
    }
}

func Get(url string) (resp *Response, err error) {
    return DefaultClient.Get(url)
}

type Response struct {
    Status string // e.g. "200 OK"
    StatusCode int // e.g. 200
    Proto string // e.g. "HTTP/1.0"
    ProtoMajor int // e.g. 1
    ProtoMinor int // e.g. 0
    Header Header
    Body io.ReadCloser
    ContentLength int64
    TransferEncoding []string
    Close bool
    Uncompressed bool
    Trailer Header
    Request *Request
    TLS *tls.ConnectionState
}

type ReadCloser interface {
    Reader
    Closer
}

type Reader interface {
    Read(p []byte) (n int, err error)
}

type Closer interface {
    Close() error
}

func Copy(dst Writer, src Reader) (written int64, err error) {
    return copyBuffer(dst, src, nil)
}

func (f *File) Read(b []byte) (n int, err error) {
    if err := f.checkValid("read"); err != nil {
        return 0, err
    }
    n, e := f.read(b)
    return n, f.wrapErr("read", e)
}

func (f *File) Write(b []byte) (n int, err error) {
    if err := f.checkValid("write"); err != nil {
        return 0, err
    }
    n, e := f.write(b)
    if n < 0 {
        n = 0
    }
    if n != len(b) {
        err = io.ErrShortWrite
    }

    epipecheck(f, e)

    if e != nil {
        err = f.wrapErr("write", e)
    }

    return n, err
}

IEnumerable<int> list = new List<int>();　

package main

import (
    "fmt"
)

type eat interface{
    eat()(string)
}

type Bird struct
{
    Name string 
}

func (bird Bird) eat()string{
    return "Bird:"+bird.Name+" eat"
}

func print(e eat){
    fmt.Println(e.eat())
}

// main 是应用程序的入口
func main() {

    bird1:= Bird{Name:"Big"}
    bird2:= new(Bird)
    bird2.Name = "Small"

    print(bird1)
    print(bird2)

    var eat1 eat
    eat1 = bird1
    print(eat1)
}

package main

import (
    "fmt"
)

type notifier interface {
    notify()
}

type user struct {
    name string
    email string
}

func (u user) notify() {
    fmt.Printf("Sending user email to %s<%s>\n",
        u.name,
        u.email)
}

func sendNotification(n notifier) {
    n.notify()
}

func main() {
    u := user{"Bill", "bill@email.com"}
    sendNotification(u)

}

func (u *user) notify() {
    fmt.Printf("Sending user email to %s<%s>\n",
        u.name,
        u.email)
}

func main() {
    u := user{"Bill", "bill@email.com"}
    sendNotification(u)
}

cannot use u (type user) as type notifier in argument to sendNotification:user does not implement notifier (notify method has pointer receiver)

func (u *user) notify() {

    fmt.Printf("Sending user email to %s<%s>\n",

        u.name,

        u.email)

}

func main() {

    u := user{"Bill", "bill@email.com"}

    sendNotification(&u)

}

package main
import (
    "fmt"
)
type People interface {
    Speak(string) string
}
type Stduent struct{}
func (stu *Stduent) Speak(think string) (talk string) {
    if think == "bitch" {
        talk = "You are a good boy"
    } else {
        talk = "hi"
    }
    return
}
func main() {
    var peo People = Stduent{}
    think := "bitch"
    fmt.Println(peo.Speak(think))
}

// Sample program to show how polymorphic behavior with interfaces.
package main

import (
    "fmt"
)

type notifier interface {
    notify()
}

// user defines a user in the program.
type user struct {
    name string
    email string
}

func (u *user) notify() {
    fmt.Printf("Sending user email to %s<%s>\n",
        u.name,
        u.email)
}

type admin struct {
    name string
    email string
}

func (a *admin) notify() {
    fmt.Printf("Sending admin email to %s<%s>\n",
        a.name,
        a.email)
}

// main is the entry point for the application.
func main() {
    // Create a user value and pass it to sendNotification.
    bill := user{"Bill", "bill@email.com"}
    sendNotification(&bill)

    // Create an admin value and pass it to sendNotification.
    lisa := admin{"Lisa", "lisa@email.com"}
    sendNotification(&lisa)
}

func sendNotification(n notifier) {
    n.notify()
}