How to Access Struct Field Tag Values Using Go's Reflection Package?

Accessing Field Tag Values with Go's Reflection Package

Question:

How can I access the tag values of a specific struct field using the Go reflection package?

Answer:

While reflecting on a struct, it is not possible to directly retrieve the tag values of a specific field by providing its value. This is because the reflection package cannot automatically associate the value with the original struct.

To obtain the tag values, you need to obtain the reflect.StructField associated with the field. Here's how you can do it:

import "reflect"

type User struct {
    name    string `json:name-field`
    age     int
}

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

// ...

user := &User{"John Doe The Fourth", 20}
field, ok := reflect.TypeOf(user).Elem().FieldByName("name")
if ok {
    tag := getStructTag(field)
    // ...
}

In this example, we obtain the reflect.StructField (field) for the "name" field by using FieldByName. We then pass field to the getStructTag function to retrieve the tag value.

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