Scala Set

原创转载请注明出处：http://agilestyle.iteye.com/blog/2332524

Class hierarchy for Scala sets

package org.fool.scala.basic

import scala.collection.mutable

object ScalaSet {
  def main(args: Array[String]): Unit = {
    var set = Set("a", "b")
    // true
    println(set.isInstanceOf[scala.collection.immutable.Set[String]])
    // false
    println(set.isInstanceOf[scala.collection.mutable.Set[String]])

    // set = set + "ab"
    set += "ab"
    // true
    println(set.isInstanceOf[scala.collection.immutable.Set[String]])
    // false
    println(set.isInstanceOf[scala.collection.mutable.Set[String]])
    println(set)

    val shuSet = mutable.Set("guanyu", "zhangfei")
    shuSet += "zhaoyun"
    // false
    println(shuSet.isInstanceOf[scala.collection.immutable.Set[String]])
    // true
    println(shuSet.isInstanceOf[scala.collection.mutable.Set[String]])
    println(shuSet)
  }
}

Console Output