IntelliJ IDEA 2020.1 Help

Kotlin

Parameter hints

Show property type hints

Controls whether hints should appear when assigning a value to a property whose type is not explicitly specified.

class User(_id: Int = 0) { val id = _id // inferred property type }

Show function return type hints

Controls whether hints should appear for functions with inferred return types.

fun sum(i1: Int, i2: Int) = i1 + i2 // the return type (Int) is inferred

Show local variable type hints

Controls whether hints should show the type when a local variable, whose type is not specified, is assigned some value. The type is not shown for constants.

fun returnHello(): String = "Hello" fun hintsDemo() { val s = returnHello() // "s" gets the String type }

Show parameter type hints

Controls whether hints should appear for lambda parameters without a type.

fun hintsDemo() { listOf(1, 2, 3).filter { elem -> // parameter with inferred type elem >= 3 } }

Show argument name hints

Controls whether hints should appear for function and constructor arguments.

data class User(val id: Int) fun printSum(a: Int, b: Int) { println(a + b) } fun hintsDemo() { val u = User(0) // calling constructor printSum(1, 1) // calling function }

Show lambda return expression hints

Controls whether hints should appear for multiline lambdas that return a value. This is useful in complex constructs, where it is easy to forget that a lambda is returning something.

fun numbers(): String { val numbers = StringBuilder() return with(numbers) { // "with" structure starts here for (letter in '0'..'9') { append(letter) } toString() // used as the return value } }

Show hints for implicit receivers and parameters of lambdas

Controls whether hints should appear for lambdas' implicit receivers.

fun numbers(): String { val numbers = StringBuilder() return with(numbers) { // the implicit receiver is "numbers" (StringBuilder) for (letter in '0'..'9') { append(letter) } toString() } }

Show hints for suspending calls

Controls whether hints should appear for suspending calls.

fun hintsDemo() { doSomethingUsefulOne() // calling a suspending function } suspend fun doSmth(){ delay(1000L) println("Inside a suspending function") }

Black list

Allows you to specify classes for which inlay hints will not be displayed.

Last modified: 7 July 2020