Extract value from an array in a Json - json

Question

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?

Answer 1

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