Kotlin

Question

我有一个函数接受 Article 和可空方法，并以 Article 作为接收者。我只想调用可为 nullable 的方法，并且 return 仅当它存在时才调用它的结果。我该怎么做？

fun foo(article: Article, method: (Article.() -> String)? = null): String? =
    article?.method() // how can I do this?

Answer 1

fun foo(article: Article, method: (Article.() -> String)? = null): String? =
    method?.invoke(article)

或

fun foo(article: Article, method: (Article.() -> String)? = null): String? =
    method?.let { article.it() }

Kotlin - 如何仅在接收者存在时调用可为空的方法？