Golang Reflection Example

reflection.go

package main

import (
	"fmt"
	"reflect"
)

type Location struct {
	Lat float64 `json:"lat"`
	Lon float64 `json:"lon"`
}

type Foo struct {
	FirstName string   `json:"first_name"`
	Age       int      `json:"age"`
	Loc       Location `json:"location"`
}

func analyze(o any) {
	val := reflect.ValueOf(o).Elem()

	for i := 0; i < val.NumField(); i++ {

		valueField := val.Field(i)
		kind := valueField.Kind()
		type_ := valueField.Type()
		typeField := val.Type().Field(i)
		tag := typeField.Tag

		fmt.Printf("Field Name: %s,\t Field Value: %v,\t Tag Value: %s\n", typeField.Name, valueField.Interface(), tag.Get("json"))
		fmt.Printf("      Kind: %s,\t Type: %s\n", kind, type_)
	}
}

func main() {
	f := &Foo{
		FirstName: "Drew",
		Age:       30,
		Loc:       Location{Lat: 42.1, Lon: -37.2},
	}

	analyze(f)
}