Working effectively with lambda expressions

In this recipe, we are going to explore the concept of lambdas and closures. We are going to write part of an Android application code responsible for handling button-click actions.

Getting ready

In order to implement this recipe's code, you need to create a new Android application project using Android Studio IDE.

Let's assume we have the following class, which is a sort of a controller of the application view layer:

class RegistrationScreen : Activity() {
    private val submitButton: Button by lazy { findViewById(R.id.submit_button) }  

    override fun onCreate(savedInstanceState: Bundle?) {

        // hook function called once the screen is displayed
    }
}

It contains...