golang之interface（接口）与 reflect 机制

一、概述

　　什么是interface，简单的说，interface是一组method的组合，通过interface来定义对象的一组行为；

　　interface类型定义了一组方法，如果某个对象实现了某个接口的所有方法，则此对象就实现了此接口；

 package main

 import "fmt"

 type Human struct {
     name  string
     age   int
     phone string
 }

 type Student struct {
     Human  //匿名函数
     school string
     loan   float32
 }

 type Employee struct {
     Human
     company string
     money   float32
 }

 //Human对象实现Sayhi方法
 func (h *Human) Sayhi() {
     fmt.Printf("hi, I am %s you can call me on %s\n", h.name, h.phone)
 }

 //Human对象实现了Sing方法
 func (h *Human) Sing(lyrics string) {
     fmt.Println("lalala...", lyrics)
 }

 //Human对象实现了Guzzle方法
 func (h *Human) Guzzle(beerStein string) {
     fmt.Println("Guzzle Guzzle...", beerStein)
 }

 //Student 实现了BorrowMoney方法
 func (s *Student) BorrowMoney(amount float32) {
     s.loan += amount
 }

 //Empolyee 重载了Human的Sayhi的方法
 func (e *Employee) Sayhi() {
     fmt.Printf("hi, I am %s, I work at %s. call me on %s\n", e.name, e.company, e.phone)
 }

 //Employee实现了SpendSalary的方法
 func (e *Employee) SpendSalary(amount float32) {
     e.money -= amount
 }

 //define interface
 /*
 type Men interface {
     Sayhi()
     Sing(lyrics string)
     Guzzle(beerStein string)
 }

 type YoungChap interface {
     Sayhi()
     Sing(song string)
     BorrowMoney(amount float32)
 }

 type ElderlyGent interface {
     Sayhi()
     Sing(song string)
     SpendSalary(amount float32)
 }
 */

 //interface Men被Human，Student, Employee都实现
 // Student, Employee包含了Human匿名字段，所有也包含了其接口实现
 type Men interface {
     Sayhi()
     Sing(lyrics string)
 }

 func main() {
     mike := Student{Human{"Mike", , "22-22-xx"}, "MIT", 0.00}
     paul := Student{Human{"paul", , "23-32-xx"}, "Harvard", 5.00}
     sam := Employee{Human{"Sam", , "33-33-33"}, "Gling inc", }
     Tom := Employee{Human{"Tom", , "33-334-11"}, "Things ltd", }

     var i Men //interface type
     i = &mike
     fmt.Println("this is Mike, a Student\n")
     i.Sayhi()
     i.Sing("my name is Mike")

     i = &Tom
     fmt.Println("this is Tom, an employee\n")
     i.Sayhi()
     i.Sing("my name is Tom")

     x := make([]Men, )
     x[], x[], x[] = &paul, &sam, &mike
     for _, value := range x {
         value.Sayhi()
     }
 }

二、反射机制

 package main

 import (
     "fmt"
     "reflect"
 )

 func main() {
     var x float64 = 3.4
     p := reflect.ValueOf(&x)
     v := p.Elem()
     fmt.Println(v)
     v.SetFloat(8.3)
     fmt.Println(v)
 }