shigemk2 https://blog.hatena.ne.jp/shigemk2/ by shigemk2 https://www.shigemk2.com/ Scala ListにListでマイナスはできないっぽい。 逆にMapにプラスは出来る。 複数のListの差分をとりたいときはdiffを使う。 scala> List(1,2,3) - List(2,3) <console>:11: error: value - is not a member of List[Int] List(1,2,3) - List(2,3) ^ scala> val a = Map("hoge" -> 1) a: scala.collection.immutable.Map[String,Int] = Map(hoge -> 1) scala> a + ("fuga" -> 2)… 190 <iframe src="https://hatenablog-parts.com/embed?url=https%3A%2F%2Fwww.shigemk2.com%2Fentry%2Fchotto_scala_20151103" title="Scalaのちょっとしたやり取り MapやListに追加とか差分とか - by shigemk2" class="embed-card embed-blogcard" scrolling="no" frameborder="0" style="display: block; width: 100%; height: 190px; max-width: 500px; margin: 10px 0px;"></iframe> Hatena Blog https://hatena.blog 2015-11-03 15:40:02 rich https://www.shigemk2.com/entry/chotto_scala_20151103 1.0 100%