Kotlin Standard Library Cookbook

How to do it...

1. Define an initial value for the temperature variable:

val initialValue = 1

2. Declare the listener for the variable that will be observed:

val initialValue = 1val changesListener: (KProperty<*>, Int, Int) -> Unit =        { _, _: Int, newValue: Int -> println("Current temperature: $newValue") }

3. Declare the temperature variable, delegating its value to the ReadWriteProperty instance returned by the Delegates.observable() function:

val initialValue = 1val changesListener: (KProperty<*>, Int, Int) -> Unit =        { _, _: Int, newValue: Int -> println("Current temperature: $newValue") }var temperature: Int by Delegates.observable(initialValue, changesListener)