A lambda that takes no parameters

Question

In Kotlin I would like to create a lambda that takes no parameters and returns nothing. I know how to do this when it takes a string parameter and returns nothing:

private var mOnTextWatcherCallback: ((m: String) -> Unit)? = null

But how do I do it for no parameters?

Answer 1

Just use empty parentheses:

private var mOnTextWatcherCallback: (() -> Unit)? = null
//                                   ^^