Kotlin-如何在列表中找到重复值的数量?

查找列表中所有重复值的一种方法是使用 groupingBy 然后过滤以下值: > 1 . 例如。

val list = listOf("orange", "apple", "apple", "banana", "water", "bread", "banana")
println(list.groupingBy { it }.eachCount().filter { it.value > 1 })

输出

{apple=2, banana=2}

list.count { it == "apple" }

文档: https://kotlinlang.org/api/latest/jvm/stdlib/kotlin.collections/-list/ , https://kotlinlang.org/api/latest/jvm/stdlib/kotlin.collections/count.html