list - 如何获得两个列表之间的差异？

Question

我有两个清单：

val list1 = List("word1","word2","word2","word3","word1")
val list2 = List("word1","word4")

我想从中删除所有出现的list2元素list1，即我想要

List("word2","word2","word3") <= list1 *minus* list2

我这样做了list1 diff list2 ，这让我List("word2","word2","word3","word1")只删除了第一次出现的“word1”。

我无法将其转换为集合，因为我需要有关重复项的知识（请参阅上面的“word2”）。该怎么办？

score 74 · Accepted Answer

您可以使用

val unwanted = list2.toSet
list1.filterNot(unwanted)

删除所有项目list2（您不需要了解中的重复项list2）。

score 10 · Accepted Answer

val list1 = List("word1","word2","word2","word3","word1")
val list2 = List("word1","word4") 
list1 diff list2

这会做到的。

score 9 · Accepted Answer

你可以试试这个：

val list1 = List("word1","word2","word2","word3","word1")
val list2 = List("word1","word4")

println(list1.filterNot(list2.contains(_)))

3 回答 3