Creating a struct type dynamically at runtime using a Hashmap!!!😳

#go

WTF are we even talking about???

Well, we can create struct types (NOTE: types, not just variables😒) dynamically, based on the keys and the types of each individual value in a given hashmap... Yes!!!

Dynamically! During runtime!! From a Hashmap!!! A new struct type!!!! And use it of'course😃

Here is full code with the relevant method (mapToStruct), and usage example:

package main

import (
    "fmt"
    "reflect"
    "strings"
)

func mapToStruct(m map[string]interface{}) reflect.Value {
    var structFields []reflect.StructField

    for k, v := range m {
        sf := reflect.StructField{
            Name: strings.Title(k),
            Type: reflect.TypeOf(v),
        }
        structFields = append(structFields, sf)
    }

    // Creates the struct type
    structType := reflect.StructOf(structFields)

    // Creates a new struct
    return reflect.New(structType)
}

func verifyStructFields(sr reflect.Value){
    fmt.Println("\n---Fields found in struct..")

    val := reflect.ValueOf(sr.Interface()).Elem()
    for i := 0; i < val.NumField(); i++ {
        fmt.Println(val.Type().Field(i).Name)
    }
}

func setStructValues(sr reflect.Value){
    fmt.Println("\n---Setting struct fields...")
    sr.Elem().FieldByName("Name").SetString("Joe")
    sr.Elem().FieldByName("Surname").SetString("Biden")
    sr.Elem().FieldByName("Age").SetInt(79)
}

func main() {
    m := make(map[string]interface{})

    m["name"] = "Donald"
    m["surname"] = "Trump"
    m["age"] = 72

    sr := mapToStruct(m)
    fmt.Println("\n---Created type:", reflect.ValueOf(sr).Kind())

    verifyStructFields(sr)
    setStructValues(sr)

    fmt.Printf("\n---Dynamically created and initialized struct:\n%#v", sr)
}