golang 运行这个：https：//play.golang.org/p/BWDlpVkoru

Posted 2021-05-24

package main

import (
	"fmt"
)

type Gettable interface {
  Name() string
}

type gettable struct {
  name string
}
func (g *gettable) Name() string {
  return g.name
}

func (g *gettable) SetName(name string) {
  g.name = name
}

func main(){
  g := &gettable{"some name"}
  fmt.Println("original:", g.Name())
  
  // interfaces don't really have to exist anywhere except on a var
  var settable interface{
    SetName(string)
  }
  settable = g
  settable.SetName("a new name")
  fmt.Println("new:", g.Name())

  // you can define types inside method bodies
  type setter interface {
    SetName(string)
  }
  var s setter = g
  s.SetName("yet another name")
  fmt.Println("new 2:", g.Name())
}

golang 当你超过一个字符串https://play.golang.org/p/T_O4fOHcBmW时会发生什么

import (
    "fmt"
)

func main() {
    for i, t := range []byte("我我"){
        fmt.Printf("%d, %x\n",i,t)
    }
    for i, t := range string("我我"){
        fmt.Printf("%d, %x\n",i,t)
    }
    for i, t := range []rune("我我"){
        fmt.Printf("%d, %x\n",i,t)
    }
}

/* Output:
0, e6
1, 88
2, 91
3, e6
4, 88
5, 91
0, 6211
3, 6211
0, 6211
1, 6211

Program exited. */