匿名对象的kotlin访问属性 [英] kotlin access property of anonymous object

问题描述

如何访问匿名对象的对象的属性word

How do I access the property word of the object of the anonymous object

 fun main(args: Array<String>) {

        val sentence = "this is a nice sentence"

        val wordLengths: List<Any> = sentence.split(' ').map {
            object {
                val length = it.length
                val word = it
            }
        }

        wordLengths.forEach { it:Any -> println(it) }
    }

推荐答案

您明确声明wordLengths为List<Any>，并且Any没有word或length属性.您应该让Kotlin从map推断类型.

You are explicitly declaring wordLengths to be List<Any>, and Any doesn't have a word or length property. You should let Kotlin infer the type from map.

fun main() {
    val sentence = "This is a nice sentence"

    val wordLengths = sentence.split(' ').map {
        object {
            val word = it
            val length = it.length
        }
    }

    wordLengths.forEach {
        println("[${it.length}] ${it.word}")
    }
}

如果计划在方法之外需要此对象，则应创建必要的类或使用现有的类(例如Pair或String本身).请参见对象表达式:

If you plan on needing this object outside of the method then you should create the necessary class or use an existing class (e.g. Pair or String itself). See Object expressions:

请注意，匿名对象只能在本地和私有声明中用作类型.如果您将匿名对象用作公共函数的返回类型或公共属性的类型，则该函数或属性的实际类型将是该匿名对象的声明的超类型；如果您未声明，则为Any任何超类型.添加到匿名对象中的成员将不可访问.

Note that anonymous objects can be used as types only in local and private declarations. If you use an anonymous object as a return type of a public function or the type of a public property, the actual type of that function or property will be the declared supertype of the anonymous object, or Any if you didn't declare any supertype. Members added in the anonymous object will not be accessible.

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