Updating a mutable map counter value

val symTab = collection.mutable.HashMap[String, Int]()
def update0(s: String): Unit = {

  if (symTab.contains(s)) {

    symTab(s) = symTab(s) + 1

  }

  else {

    symTab(s) = 1

  }

}

// Do this instead

def update1(s: String): Unit = symTab(s) = symTab.getOrElse(s, 0) + 1

scala> update1("x")

scala> symTab("x")

res2: Int = 1

scala> update1("x")

scala> symTab("x")

res4: Int = 2