with

with

this

val person = with(Person()) {
      name = "Tony Stark"
      age = 52
      // More such stuff
      this
}

Calls the specified function

[block]

with the given

[receiver]

as its receiver and returns its result.

person

Person

this

.apply { ... }

with

val person = Person().apply {
  name = "Tony Stark"
  age = 52
}

forEach

let

with

apply

Person(init: () -> Person)

val person = Person {
   name = "Tony Stark"
   age = 32
}

fun person(init: Person.() -> Unit) = Person().apply(init)

data class Person(var name: String = "", var age: Int = -1)

fun Person(op: Person.() -> Unit) = Person().apply(op)

val brian = Person {
    name = "Brian"
    age = 26
}

fun main(args: Array<String>) {
    println(brian)
}