标签：imp mutable yield 操作 tab aaa keyset logs new
构造映射：
val score = Map[String, Int]()
val score1 = HashMap[String, Int]()
val value1 = Map[String, Int]("aa" -> 1, "bb" -> 2)
val value2 = Map[String, Int](("aa", 1), ("bb", 2))
获取映射值：
println(if(value2.contains("cc")) value2("cc") else 0)
println(value2.getOrElse("cc", 0))
println(value2.getOrElse("aa", 0))
更新映射值：
score1("aa") = 1
score1("bb") = 2
score1 += ("cc" -> 3, "dd" -> 4)
score1 += (("cc", 3), ("dd", 4))
score1 -= "cc"
迭代映射：
for((k,v) <- value2){
println(k)
println(v)
}
value2.keySet
println(value2.values)
for (v <- value2.values) println(v)
println(for ((k, v) <- value2 ) yield {(v, k)})
与Java互操作：(java.util.Properties 转 scala.collection.mutable.Map)
val prop = new Properties()
prop.put("aaa", "1")
prop.put("bba", "2")
import scala.collection.JavaConversions.propertiesAsScalaMap
val scalaMap: scala.collection.mutable.Map[String, String] = prop
scalaMap.foreach(println)
快学Scala 第五课 （构造映射，获取映射值，更新映射值，迭代映射，与Java互操作）
标签：imp mutable yield 操作 tab aaa keyset logs new
原文地址：http://www.cnblogs.com/AK47Sonic/p/7271094.html
