How to check if a "lateinit" variable has been initialized?

Question

I wonder if there is a way to check if a lateinit variable has been initialized. For example:

class Foo() {      private lateinit var myFile: File      fun bar(path: String?) {         path?.let { myFile = File(it) }     }      fun bar2() {         myFile.whateverMethod()         // May crash since I don't know whether myFile has been initialized     } } 

Answer 1

There is a lateinit improvement in Kotlin 1.2 that allows to check the initialization state of lateinit variable directly:

lateinit var file: File      if (this::file.isInitialized) { ... } 

See the annoucement on JetBrains blog or the KEEP proposal.

UPDATE: Kotlin 1.2 has been released. You can find lateinit enhancements here:

• Checking whether a lateinit var is initialized
• Lateinit top-level properties and local variables