Go指南练习_Stringer

import "fmt"

type IPAddr [4]byte

// TODO: Add a "String() string" method to IPAddr.

func (v IPAddr) String() string{  
    return fmt.Sprintf("%v.%v.%v.%v", v[0],v[1],v[2],v[3])  
}  

func main() {
    hosts := map[string]IPAddr{
        "loopback":  {127, 0, 0, 1},
        "googleDNS": {8, 8, 8, 8},
    }
    for name, ip := range hosts {
        fmt.Printf("%v: %v\n", name, ip)
    }
}