英文:
Extract value from an array in a Json
问题
我正在尝试获取"boots"的值
我的主要函数
var json := `{
"identifier": "1",
"name": "dumbname",
"person": {
"items": null,
"inventory": [
{
"T-shirt": "black",
"Backpack": {
"BigPocket": {
"spell": "healing",
"boots": "speed",
"shampoo": "Head & Shoulders"
}
}
}
],
"Pockets": null
}
}`
var res map[string]interface{}
json.Unmarshal([]byte(json), &res)
test(res)
测试函数
func test(t interface{}) {
switch reflect.TypeOf(t).Kind() {
case reflect.Slice:
s := reflect.ValueOf(t)
for i := 0; i < s.Len(); i++ {
fmt.Println(s.Index(i))
}
}
}
但是当我编译时什么都没有得到
如果有其他方法可以获取Json中的"boot"值吗?
英文:
I'm trying to get "boots" value
My func main
varjson:=`{
"identifier": "1",
"name": "dumbname",
"person": {
"items": null,
"inventory": [
{
"T-shirt": "black",
"Backpack": {
"BigPocket": {
"spell": "healing",
"boots": "speed",
"shampoo": "Head & Shoulders"
}
}
}
],
"Pockets": null
}
}`
var res map[string]interface{}
json.Unmarshal([]byte(varjson), &res)
test(res)
test function
func test(t interface{}) {
switch reflect.TypeOf(t).Kind() {
case reflect.Slice:
s := reflect.ValueOf(t)
for i := 0; i < s.Len(); i++ {
fmt.Println(s.Index(i))
}
}
}
But when I compile I get nothing
If is there another way to get the "boot" value in the Json?
答案1
得分: 1
假设你可以使用类型,根据你的评论(幸运的是,我完全同意colm的观点,尝试反映结构是困难的)。
一旦你有了一个类型,导航就非常容易。
具体来说,fmt.Println(res.Person.Inventory[0].Backpack.BigPocket.Boots)
将返回 boots
的值。需要注意的是,Inventory
是一个切片,所以你可能需要遍历它,而我在这里直接访问了它,如果 Inventory
是空的或者有其他元素,这样做是不好的。
package main
import (
"encoding/json"
"fmt"
)
type AutoGenerated struct {
Identifier string `json:"identifier"`
Name string `json:"name"`
Person struct {
Items interface{} `json:"items"`
Inventory []struct {
TShirt string `json:"T-shirt"`
Backpack struct {
BigPocket struct {
Spell string `json:"spell"`
Boots string `json:"boots"`
Shampoo string `json:"shampoo"`
} `json:"BigPocket"`
} `json:"Backpack"`
} `json:"inventory"`
Pockets interface{} `json:"Pockets"`
} `json:"person"`
}
func main() {
var varjson = `{
"identifier": "1",
"name": "dumbname",
"person": {
"items": null,
"inventory": [
{
"T-shirt": "black",
"Backpack": {
"BigPocket": {
"spell": "healing",
"boots": "speed",
"shampoo": "Head & Shoulders"
}
}
}
],
"Pockets": null
}
}`
var res AutoGenerated
json.Unmarshal([]byte(varjson), &res)
fmt.Println(res.Person.Inventory[0].Backpack.BigPocket.Boots)
}
在你的原始代码中,问题在于你的 switch
语句只覆盖了一个切片,但初始对象是一个映射。所以你的 switch
最初找不到匹配项。
英文:
Assuming you can use types, based on your comment (thankfully cause totally agree with colm, trying to reflect the structure is rough.
Once you have a type its super easy to navigate.
specifically fmt.Println(res.Person.Inventory[0].Backpack.BigPocket.Boots)
would net you the boots value. Bearing in mind that Inventory is a slice so you probably need to iterate over that, whereas here I have directly accessed it, which will be bad if Inventory is empty or there are other elements.
package main
import (
"encoding/json"
"fmt"
)
type AutoGenerated struct {
Identifier string `json:"identifier"`
Name string `json:"name"`
Person struct {
Items interface{} `json:"items"`
Inventory []struct {
TShirt string `json:"T-shirt"`
Backpack struct {
BigPocket struct {
Spell string `json:"spell"`
Boots string `json:"boots"`
Shampoo string `json:"shampoo"`
} `json:"BigPocket"`
} `json:"Backpack"`
} `json:"inventory"`
Pockets interface{} `json:"Pockets"`
} `json:"person"`
}
func main() {
varjson := `{
"identifier": "1",
"name": "dumbname",
"person": {
"items": null,
"inventory": [
{
"T-shirt": "black",
"Backpack": {
"BigPocket": {
"spell": "healing",
"boots": "speed",
"shampoo": "Head & Shoulders"
}
}
}
],
"Pockets": null
}
}`
var res AutoGenerated
json.Unmarshal([]byte(varjson), &res)
fmt.Println(res.Person.Inventory[0].Backpack.BigPocket.Boots)
}
In your original, whats wrong is your switch statement only covers a slice, but the initial object is a map. So your switch is not finding a match initially
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