with the named arguments and default arguments, do you still use the pattern builder in Kotlin ?

@gaspard The builder patten is useful when interoperating with Java and when making DSLs.

Same here - when providing API to Java or DSL.

I've only just started on Kotlin and I'm ploughing through Kotlin in Action. In there they say you can use apply() to do what is often achieved by a builder in Java. I've found it useful when creating objects from Java classes where they don't have named arguments or default values on constructors (eg where you have a pojo with a single default constructor).

Yes that is a common use case for

apply {}

indeed. If the pojo is written in Kotlin though and isn't expected to be used from Java a lot, it is usually more appropriate to use named arguments.