This Expression

To denote the current receiver, we use this{: .keyword } expressions:

• In a member of a class, this{: .keyword } refers to the current object of that class
• In an extension function or a function literal with receiver, this{: .keyword } denotes the receiver parameter that is passed on the left-hand side of a dot.

If this{: .keyword } has no qualifiers, it refers to the innermost enclosing scope. To refer to this{: .keyword } in other scopes, label qualifiers are used:

Qualified this{: .keyword }

{:#qualified}

To access this{: .keyword } from an outer scope (a class, or extension function, or labeled function literal with receiver) we write this@label where @label is a label on the scope this{: .keyword } is meant to be from:

class A { // implicit label @A
  inner class B { // implicit label @B
    fun Int.foo() { // implicit label @foo
      val a = this@A // A's this
      val b = this@B // B's this

      val c = this // foo()'s receiver, an Int
      val c1 = this@foo // foo()'s receiver, an Int

      val funLit = lambda@ fun String.() {
        val d = this // funLit's receiver
      }


      val funLit2 = { s: String ->
        // foo()'s receiver, since enclosing lambda expression
        // doesn't have any receiver
        val d1 = this
      }
    }
  }
}