Maybe this sort of thing doesn’t happen too often, but it’s something I’ve started noticing more and more as I read code in the wild.ĭid I miss a case where takeIf() and takeUnless() would be appropriate, or a case when they introduce errors? Let me know, I’m always happy to chat and appreciate feedback. MutableSet implements Set, so any class implementing MutableSet needs to implement both. It generates no-arg constructors for any class annotated with Entity, MappedSuperclass or Embeddable. We can rewrite any statement without return type as an. On the other hand, it feels like calling takeIf() or takeUnless() on an expression should at least be a warning in IntelliJ. In Kotlin, we have two way to define a function or a method: as a statement, with the above syntax similar to Java or as an expression. The takeIf() and takeUnless() functions aren’t doing anything you can’t do with if/else, it just makes things easier to read in some cases (which I value highly when writing code).

I like the fact if is an expression in Kotlin, and I think that reduces some of the utility of takeIf() and takeUnless(). I do find places in my code to use it, but more often than not I use an if/else expression instead. Closing ThoughtsĪs we’ve seen, the places where we might use takeIf() and takeUnless() can be fairly subjective. We can use Java collections, but Kotlin provides a good set of native interfaces. For example, if you have a Java method that takes a as a parameter, you can pass any Collection or Mutable Collection value as an argument to that parameter.

In Kotlin the Any type represents the super type of all non-nullable. When you need to call a Java method and pass a collection as an argument, you can do so directly without any extra steps. takeIf Īgain, it’s subjective that the takeIf() version is any better, but some might find easier to read. Object is the root of the class hierarchy in Java, every class has Object as a superclass.

Any kotlin example