如何获得两个列表之间的差异? [英] How to get the difference between two lists?

问题描述

我有两个列表:

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

我想从 list1 中删除所有出现的 list2 元素，即我想要

I want to remove all occurrences of list2 elements from list1, i.e. I want

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

我做了 list1 diff list2 这给了我 List("word2"，"word2"，"word3"，"word1")，该列表仅删除了第一次出现的"word1".

I did list1 diff list2 which gives me List("word2","word2","word3","word1") which is removing only the first occurrence of "word1".

我无法将其转换为集合，因为我需要有关重复项的知识(请参见上面的"word2").该怎么办?

I cannot convert it to sets because I need knowledge about duplicates (see "word2" above). What to do?

推荐答案

您可以使用

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

删除 list2 中的所有项目(您不需要了解 list2 中的重复项).

to remove all items in list2 (you don't need knowledge of duplicates in list2).

这篇关于如何获得两个列表之间的差异?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！