go接口

1、go通过接口将所有共性的方法进行统一处理，类比理解c++的多态
2、interface可以类比为protocal，理解为双方为交流而做出的约定
3、interface是golang里面的抽象类型（类型的一种）！！！


//定义接口
type AirIF interface {
   fly()
}

//定义结构体
type bird struct{
}

//定义结构体
type human struct{
}

//注：两个结构体bird、human都有接口里所有方法的共有属性
//examp：
func (bird)fly(){
}
func (human)fly(){
}

 

转自：https://www.runoob.com/go/go-interfaces.html

package main

import (
    "fmt"
)

type Phone interface {
    call()
}

type NokiaPhone struct {
}

func (nokiaPhone NokiaPhone) call() {
    fmt.Println("I am Nokia, I can call you!")
}

type IPhone struct {
}

func (iPhone IPhone) call() {
    fmt.Println("I am iPhone, I can call you!")
}

func main() {
    var phone Phone

    phone = new(NokiaPhone)
    phone.call()

    phone = new(IPhone)
    phone.call()

}


编译：
I am Nokia, I can call you!
I am iPhone, I can call you!

package main

import (
    "fmt"
    "math"
)

type geometry interface {
    area() float64
    perim() float64
}

type rect struct {
    width, height float64
}
type circle struct {
    radius float64
}

func (r rect) area() float64 {
    return r.width * r.height
}
func (r rect) perim() float64 {
    return 2*r.width + 2*r.height
}

func (c circle) area() float64 {
    return math.Pi * c.radius * c.radius
}
func (c circle) perim() float64 {
    return 2 * math.Pi * c.radius
}

func measure(g geometry) {
    fmt.Println(g)
    fmt.Println(g.area())
    fmt.Println(g.perim())
}

func main() {
    r := rect{width: 3, height: 4}
    c := circle{radius: 5}

    measure(r)
    measure(c)
}


编译：
{3 4}
12
14
{5}
78.53981633974483
31.41592653589793