Golang : How to get struct tag and use field name to retrieve data?



Tags : golangstruct-field struct-tag field-by-name

Problem :

A structure data field can have additional information or meta-data. This information is known as struct tag in Golang. You want to find out a struct data field type's struct tag. How to that with the reflect package?

NOTE : Don't confuse field name and struct tag yeah!

Solution :

Use the reflect package StructField type to retrieve the data.

Here you go !

 package main

 import (
  "fmt"
  "reflect"
 )

 type Person struct {
  Name string `json:name`
 }

 func getStructTag(f reflect.StructField) string {
  return string(f.Tag)
 }

 func main() {
  user := &Person{"Adam"}

  field, ok := reflect.TypeOf(user).Elem().FieldByName("Name") // not json:name

  if !ok {
 panic("Field not found")
  }

 // get the struct field tag
 // see http://golang.org/pkg/reflect/#StructField
  fmt.Println(getStructTag(field)) // json:name

  //----- get data from the initialized Person struct
  //----- based on the field name

  r := reflect.ValueOf(user)

  f := reflect.Indirect(r).FieldByName("Name")
  fmt.Println(f)

 }

Output :

json:name

Adam

Happy coding !

References :

http://golang.org/pkg/reflect/#StructField

http://golang.org/pkg/reflect/#StructTag

Affiliate :

Hire Golang Developers


  See also : Golang : How to get struct field and value by name



Tags : golangstruct-field struct-tag field-by-name

By Adam Ng

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