// TestStruct comment
type TestStruct struct {
    A string `json:"jsona",xml:"xmla"`
}

package main

import (
    "fmt"
    "reflect"
)

// TestStruct comment
type TestStruct struct {
    A string `json:"jsona",xml:"xmla"`
}

func main() {

    var theStruct = TestStruct{"A"}

    fmt.Println("First field tag: ", reflect.TypeOf(theStruct).Field(0).Tag)
    fmt.Println("Json tag value:  ", reflect.TypeOf(theStruct).Field(0).Tag.Get("json"))
    fmt.Println("XML tag value:   ", reflect.TypeOf(theStruct).Field(0).Tag.Get("xml"))
}

First field tag:  json:"jsona",xml:"xmla"
Json tag value:   jsona
XML tag value: