Hands-On Microservices with Kotlin

Lambda

Considering that we just use a range of numbers that we cycle in a loop:

fun printNumbers(){  val range = 1..10  for(i in range){    println(i)  }}

We could use a lambda to access them:

fun printNumbers(){  val range = 1..10  range.forEach { i -> println(i) }}

But lambda could be easily shortened with the inferred it object:

fun printNumbers(){  val range = 1..10  range.forEach { println(it) }}

And we don't really need a variable for it, so we could simplify it with:

fun printNumbers() {  (1..10).forEach { println(it) }}

But since we just print the elements of forEach, we could just use a method reference instead of the lambda:

fun printNumbers() {  (1..10).forEach(::println)}

These were just some examples of some of the Kotlin idioms, but there ...