Scala列表基于用户输入过滤：如何得到指定匹配结果？

Hey there! Let's work through this list filtering problem in Scala step by step.

First, let's clarify the core requirements from your example:

• Keep elements that contain the substring "ab"
• Exclude the element that is exactly equal to "ab" itself (since it's missing from your expected result)

Solution Code #

Here's a straightforward implementation using Scala's built-in filter method:

val original = List("a","ab","abc","abcd","zadad","ji","jijdf","bcab", "frab","abkcdef","opabcd")
val find = "ab"
val result = original.filter(s => s.contains(find) && s != find)

Logic Breakdown #

• filter iterates over every element in the list and retains only those that meet our condition
• s.contains(find) checks if the current string includes the target substring "ab"
• s != find ensures we exclude the exact match of "ab" (since you don't want this entry in your final result)

More Generic Version #

If you want a solution that works for any target substring (not just "ab"), you can replace the exact equality check with a length comparison. This approach automatically excludes any element that's the same length as the target (and thus can only be an exact match):

val result = original.filter(s => s.contains(find) && s.length > find.length)

Verify the Result #

Running either snippet will give you the expected output:
List("abc", "abcd", "bcab", "frab", "abkcdef", "opabcd")

内容的提问来源于stack exchange，提问作者Anil