使用嵌套数组进行JSON编组？

huangapple
go评论116阅读模式
英文:

Marshaling JSON with nested array?

问题

我想创建以下格式的JSON：

  1. {
  2.   "name": "val1",
  3.   "version": "val2",
  4.   "type": "val3",
  5.   "settings": [
  6.     "setting1",
  7.     "setting2",
  8.     "setting3",
  9.     [
  10.       "option1",
  11.       "option2"
  12.     ] 
  13.   ]
  14. }

但我不知道如何在settings内创建嵌套数组：

  1. package main
  3. import (
  4.         "encoding/json"
  5.         "fmt"
  6. )
  8. type Config struct {
  9.         Name     string   `json:"name"`
  10.         Version  string   `json:"version"`
  11.         Type     string   `json:"type"`
  12.         Settings []string `json:"settings"`
  13. }
  15. func main() {
  16.         settings := []string{"setting1", "setting2", "setting3"}
  17.         options := []string{"option1", "option2"}
  18.         setopts := append(settings, options...)
  20.         c := &Config{"val1", "val2", "val3", setopts}
  22.         j, err := json.Marshal(c)
  23.         if err != nil {
  24.                 panic(err)
  25.         }
  27.         fmt.Println(string(j))
  28. }

通过jq输出以提高可读性：

  1. $ ./main | jq
  2. {
  3.   "name": "val1",
  4.   "version": "val2",
  5.   "type": "val3",
  6.   "settings": [
  7.     "setting1",
  8.     "setting2",
  9.     "setting3",
  10.     "option1",
  11.     "option2"
  12.   ]
  13. }

结果是option1和option2是settings数组内的值，但它们应该是settings的嵌套数组内的值。而且，在编组时，选项可能不总是存在，在这些情况下，不应创建嵌套数组。

我该如何实现这个目标？

英文:

I want to create JSON like this:

  1. {
  2.   "name": "val1",
  3.   "version": "val2",
  4.   "type": "val3",
  5.   "settings": [
  6.     "setting1,
  7.     "setting2",
  8.     "setting3",
  9.     [
  10.       "option1",
  11.       "option2"
  12.     ] 
  13.   ]
  14. }

But I don't know how to create the nested array inside settings:

  1. package main
  3. import (
  4.         "encoding/json"
  5.         "fmt"
  6. )
  8. type Config struct {
  9.         Name     string   `json:"name"`
  10.         Version  string   `json:"version"`
  11.         Type     string   `json:"type"`
  12.         Settings []string `json:"settings"`
  13. }
  15. func main() {
  16.         settings := []string{"setting1", "setting2", "setting3"}
  17.         options := []string{"option1", "option2"}
  18.         setopts := append(settings, options...)
  20.         c := &Config{"val1", "val2", "val3", setopts}
  22.         j, err := json.Marshal(c)
  23.         if err != nil {
  24.                 panic(err)
  25.         }
  27.         fmt.Println(string(j))
  28. }

Output piped through jq for readability:

  1. $ ./main | jq
  2. {
  3.   "name": "val1",
  4.   "version": "val2",
  5.   "type": "val3",
  6.   "settings": [
  7.     "setting1",
  8.     "setting2",
  9.     "setting3",
  10.     "option1",
  11.     "option2"
  12.   ]
  13. }

The result is that option1 and option2 is values inside settings array, but they should be inside a nested array of settings instead. Also, the options may not always be present when marshaling and in those cases the nested array should not be created.

How can I accomplish this?

答案1

得分: 4

你在这里展示的输出可以被描述为 JSON 字符串或字符串数组。

你可以使用 []interface{} 来建模它，并向其附加字符串或切片：

  1. type Config struct {
  2.         Name     string        `json:"name"`
  3.         Version  string        `json:"version"`
  4.         Type     string        `json:"type"`
  5.         Settings []interface{} `json:"settings"`
  6. }
  8. func main() {
  9.         settings := []interface{}{
  10.               "setting1", 
  11.               "setting2", 
  12.               "setting3",
  13.               []string{"option1", "option2"},
  14.         }
  16.         c := &Config{"val1", "val2", "val3", settings}
  18.         j, err := json.Marshal(c)
  19.         if err != nil {
  20.                 panic(err)
  21.         }
  23.         fmt.Println(string(j))
  24. }

Playground: https://go.dev/play/p/8LPAVBPmd8w

英文:

The output that you show here:

  1.     "setting1",
  2.     "setting2",
  3.     "setting3",
  4.     [
  5.       "option1",
  6.       "option2"
  7.     ]

can be described as JSON string or array-of-strings.

You may model this with []interface{}, and append to it either strings or slices:

  1. type Config struct {
  2.         Name     string        `json:"name"`
  3.         Version  string        `json:"version"`
  4.         Type     string        `json:"type"`
  5.         Settings []interface{} `json:"settings"`
  6. }
  8. func main() {
  9.         settings := []interface{}{
  10.               "setting1", 
  11.               "setting2", 
  12.               "setting3",
  13.               []string{"option1", "option2"},
  14.         }
  16.         c := &Config{"val1", "val2", "val3", settings}
  18.         j, err := json.Marshal(c)
  19.         if err != nil {
  20.                 panic(err)
  21.         }
  23.         fmt.Println(string(j))
  24. }

Playground: https://go.dev/play/p/8LPAVBPmd8w

huangapple
  • 本文由 发表于 2021年12月13日 04:35:21
  • 转载请务必保留本文链接：https://go.coder-hub.com/70327490.html
  • go
  • json
匿名

发表评论

匿名网友

:?: :razz: :sad: :evil: :!: :smile: :oops: :grin: :eek: :shock: :???: :cool: :lol: :mad: :twisted: :roll: :wink: :idea: :arrow: :neutral: :cry: :mrgreen:

确定