This expressions

To denote the current receiver, you use this expressions:

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

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

Qualified this

To access this from an outer scope (a class, extension function, or labeled function literal with receiver) you write this@label, where @label is a label on the scope this 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, a String
            }

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

Implicit this

When you call a member function on this, you can omit the this. qualifier. However, if another callable with the same name is available in a closer lexical scope, Kotlin resolves the unqualified call to that callable instead of the member function. To explicitly call the member function, use the this. qualifier:

fun main() {
    class A {
        fun printLine() {
            println("Member function")
        }

        fun invokePrintLine() {
            fun printLine() {
                println("Local function")
            }
         
            printLine()
            // Local function
         
            this.printLine()
            // Member function
        }
    }

    A().invokePrintLine()
}

18 June 2026