Person.kt

<!-- Copyright 2019 Google LLC.
SPDX-License-Identifier: Apache-2.0 -->

class Person(name: String, lastname: String) {
   var name: String by FormatDelegate(name)
   var lastname: String by FormatDelegate(lastname)
   var updateCount = 0
}

Hi Murat, thanks for the great article!

I got the example to work only if I call the constructor on FormatDelegate:

   var name: String by FormatDelegate()
   var lastname: String by FormatDelegate()

Or I declare FormatDelegate a singleton object:

object FormatDelegate : ReadWriteProperty<Any?, String> {

instead of (but then formattedString got clobbered):

class FormatDelegate : ReadWriteProperty<Any?, String> {

Hi,
Thanks for reaching out, really appreciate it.
You can use "class FormatDelegate : ReadWriteProperty<Any?, String>" and it should work. Can you share me what type error you are getting?

ahh i see sorry you are correct it should be:
var name: String by FormatDelegate()
var lastname: String by FormatDelegate()

thanks again!!

The default values of name and lastname aren't written to the members. To fix this FormatDelegate could accept a default value:

class Person(name: String, lastname: String) {
   var name: String by FormatDelegate(name)
   var lastname: String by FormatDelegate(lastname)
   var updateCount = 0
}