Given an object (json), write code to extract all the keys from it.

extract_json_keys.go

func flattenJSON(source string) []string{
	return flattenJSONWorker(source, "")
}

// source is the json object and parent initially is ""
func flattenJSONWorker(source string,parent string) []string{
	res := make([]string,0)
	var arr map[string]gjson.Result

	if gjson.Parse(source).IsObject(){
		arr = gjson.Parse(source).Map()
	} else if gjson.Parse(source).IsArray(){
		for index, item := range gjson.Parse(source).Array() {
			log.Printf("%v, %v", index, item)
			var temp []string
			if parent == ""{
				temp= flattenJSONWorker(item.Raw,strconv.Itoa(index))
			}else{
				temp = flattenJSONWorker(item.Raw,parent + ".[" + strconv.Itoa(index) + "]")
			}
			res = append(res,temp...)
		}
	} else{
		return  []string{parent}
	}
	for key,val := range arr{
		var temp []string
		if parent == ""{
			temp= flattenJSONWorker(val.Raw,key)
		}else{
			temp = flattenJSONWorker(val.Raw,parent + "." + key)
		}
		res = append(res,temp...)
	}
	return res
}