问题描述
如何在 scala switch 语句中执行一个 case 块开始执行另一个 case 块.(在 java 中:没有中断的情况).
How can I do in scala switch statement which after performing one case block start perform another case block. (in java: cases without break).
switch(step) { case 0: do something; case 1: do something more; case 2: etc...; break; default: do something else; }
感谢您的帮助!
推荐答案
万一不能使用0 |1 |2 您可以使用操作列表作为解决方法,如下所示:
In case you can't use 0 | 1 | 2 you could use a list of actions as workaround like this:
def switch[T](i: T)(actions: (T, () => Unit)*)(default: => Unit) = { val acts = actions.dropWhile(_._1 != i).map{_._2} if (acts.isEmpty) default else acts.foreach{_()} } def myMethod(i: Int): Unit = switch(i)( 0 -> {() => println("do 0")}, 1 -> {() => println("do 1")}, 2 -> {() => println("do 2") return // instead of break }, 3 -> {() => println("do 3")} )(default = println("do default")) myMethod(1) // do 1 // do 2 myMethod(3) // do 3 myMethod(5) // do default