set

Set，集合。

表示没有重复的元素的集合

特点是：唯一性

默认情况下，set是不可变的，默认为 set() 或 scala.collection.immutable.Set() 可以用 scala.collection.mutable.Set()变成可变

def main(args: Array[String]): Unit = {
  val set1 =scala.collection.immutable.Set(1,2,3,1,1,1,1)
  val set2 =scala.collection.mutable.Set(1,2,3)
  set2+= 20
  println(set1)
  println(set2)
}

def main(args: Array[String]): Unit = {
  val set1=scala.collection.mutable.Set(1,2,3)
  set1+=1
  set1+=4

  set1-=2

  val value=3
  if(set1.contains(value)){
    println(s"${value}存在")
  }else{
    println(s"${value}不存在")
  }
}
val set2=scala.collection.mutable.Set("语文")
val set3=scala.collection.mutable.Set("数学")
set2 ++= set3

val set4 =scala.collection.mutable.Set("唱歌","跳舞")
val set5=scala.collection.mutable.Set("打游戏","打球","跳舞")
val set6=set4.intersect(set5)

val set7=scala.collection.mutable.Set("唱歌","跳舞")
val set8=scala.collection.mutable.Set("打游戏","打球","跳舞")
val set9=set8.diff(set7)

println(set9)
println(set6)
println(set2)