Learning Kotlin: it is a thing

Submitted by Robert MacLean on Mon, 07/09/2018 - 09:00
**More Information** * This is the 15th post in a multipart series. If you want to read more, see our [series index](/learning-kotlin-introduction) Our [last post](/learning-kotlin-collections) covered a lot of the awesome extensions to collections in Kotlin and as someone who comes from .NET and Java I think about writing Lambdas in a specific way.  val numbers = listOf(1,5,6,8,10) val evens = numbers.filter({ num -> num % 2 == 0 }) println(evens) In .NET/Java we need a range variable, in the example above it is `num` which refers to the item in the collection we are working on. Kotlin knows you will always have a range variable, so why not simplify it and make it have a common name `it`:  val numbers = listOf(1,5,6,8,10)  val evens = numbers.filter({ it % 2 == 0 })  println(evens) Here we got ride of the `num ->` start of the lambda and we can just refer to the automatically created range variable `it`.