Kotlin Cookbook

Chapter 11. Miscellaneous

This chapter consists of recipes that don’t fit any of the other headings. Here you’ll find how to make the when function exhaustive, how to measure the elapsed time of a function, and how to use the TODO function from the standard library, among many others.

11.1 Working with the Kotlin Version

Problem

You want to find out programmatically which version of Kotlin you are currently using.

Solution

Use the CURRENT property in the companion object of the KotlinVersion class.

Discussion

Since version 1.1, the kotlin package includes a class called KotlinVersion that wraps the major, minor, and patch values for the version number. Its toString method returns the combination as major.minor.patch given an instance of this class. The current instance of the class is contained in a public field called CURRENT in the companion object.

It’s therefore trivially easy to return the current Kotlin version. Just access the field KotlinVersion.CURRENT, as in Example 11-1.

Example 11-1. Printing the current Kotlin version

fun main(args: Array<String>) {
    println("The current Kotlin version is ${KotlinVersion.CURRENT}")
}

The result is the major/minor/patch version of the Kotlin compiler, such as 1.3.41. All three parts of this quantity are integers between 0 and MAX_COMPONENT_VALUE, which has the value 255.

Note

The CURRENT property is annotated as a public @JvmField in the source code, so it is available from Java as well.

The KotlinVersion class implements ...