Kotlin `this` 表达式

Tags: Kotlin


Kotlin 提供了一个 this 表达式,主要就是一个带标签的 this,用于在内部类、扩展中获取正确的类对象实例。

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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 = [email protected] 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
}
}
}
}
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