lateinit var a: String

makes it possible to have non-nullable type and yet allow for this edge case of it being null until properly assigned value AFTER construction

maciekjanusz: But using

var a = 0

can work too, avoiding autoboxing

that's beside the point of

lateinit

, you cannot use

lateinit

on properties with initializer

More accurately

lateinit

would be pointless if first init is not late, but in the initializer instead 😉