How can I filter out just one ocurrence in a string vector in Scala?

user_14735338 0
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I need to create a new vector from Vector("lumber", "stone", "magic potion","stone","lumber") but without the string "lumber", if i use the method filterNot(_=="lumber") it removes the two elements that match "lumber". is there a filter out just one ocurrence?

i tried using .distinct but i need the two stones in the vector.

scala
2 Answers

Easiest way is to use diff:

val c = Vector("lumber", "stone", "magic potion","stone","lumber")
c diff Vector("lumber")
// result: Vector(stone, magic potion, stone, lumber)
user_12700030

You can split the collection at the first occurence and then drop it:

val (pre, post) = c.span(_ == "lumber")
pre.dropRight(1) ++ post

When there is no "lumber" in the collection, pre will be empty and pre.dropRight(1) will drop nothing.

With 2.13 you can prefer a one-liner using pipe:

import scala.util.chaining._

c.span(_ == "lumber").pipe(split => split._1.dropRight(1) ++ split._2)
user_166730
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