golang:json 反序列化的[]和nil

package main

import (
	"encoding/json"
	"log"
)

type JS struct {
	A []string
}

func main() {
	v1 := &JS{}
	v2 := &JS{A: []string{}}
	o1, err := json.Marshal(&v1)
	log.Println(string(o1), err)

	o2, err2 := json.Marshal(&v2)
	log.Println(string(o2), err2)
}

结果

2019/01/07 18:13:26 {"A":null} 
2019/01/07 18:13:26 {"A":[]}