* Functions

To make your code more concise, you can use single-expression functions.
For example, the =sum()= function can be shortened

#+begin_src kotlin
  fun sum(x: Int, y: Int): Int {
      return x + y
  }

  println(sum(1,2))
#+end_src

#+RESULTS:
: 3

#+begin_src kotlin
  fun sum2(x: Int, y: Int) = x + y

  println(sum2(1,2))
#+end_src

#+RESULTS:
: 3

** Lambda expressions

You can even write lambda expressions in kotlin

#+begin_src kotlin
  fun uppercaseString(string: String): String {
      return string.uppercase()
  }

  println(uppercaseString("hello"))
#+end_src

#+RESULTS:
: HELLO

Can also be written to:

#+begin_src kotlin
  println({ string: String -> string.uppercase() }("hello"))
#+end_src

#+RESULTS:
: HELLO