Struggling to understand this. Does anyone know wh...

# android

[Johnny]

Struggling to understand this. Does anyone know what the syntax at line 2 means? And why the input is SharedPreferences.Editor.()
I get the extension function is accepting a lambda with input SharedPreferences.Editor.() but what does .() mean?

private fun SharedPreferences.edit(func: SharedPreferences.Editor.() -> Unit) {
     val editor = edit()   // 1
     editor.func()         // 2
     editor.apply()        // 3
 }

This is the code that uses the extension function

val sharedPref = requireActivity().getPreferences(Context.MODE_PRIVATE)
sharedPref.edit {
    putBoolean("hello", true)
}

[ephemient]

https://kotlinlang.org/docs/lambdas.html#function-literals-with-receiver

[Johnjake Talledo]

its a lambda func: sharedPreferences.Editor.() -> Unit