Scala两个列表的区别

Question

我有两个清单:

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

我想删除所有出现的list2元素list1,即我想要的

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

我这样做list1 diff list2 了List("word2","word2","word3","word1"),它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的知识(请参阅上面的"word2").该怎么办？

Answer 1

您可以

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

删除所有项目list2.(您不需要重复知识list2.)

Answer 2

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(_)))

Answer 3

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

这将做到。