Custom json decoding for changing one member data field

main.go

package main

import (
	"fmt"

	"encoding/json"
)

var d1 = []byte(`
{
	"ABC": {
		"Val": "hello"
	}
}
`)

var d2 = []byte(`
{
	"DEF": {
		"Val": "world"
	}
}
`)

type Inside struct {
	Val string
}

func main() {

	var objMap map[string]*json.RawMessage
	err := json.Unmarshal(d2, &objMap)
	if err != nil {
		fmt.Println(err)
		return
	}
	fmt.Println(objMap)

	var in Inside
	for k := range objMap {
		err = json.Unmarshal([]byte(*objMap[k]), &in)
		if err != nil {
			fmt.Println(err)
			return
		}
		fmt.Println(in)
	}

}