Scala 有几种其它的循环结构,scala几种循环结构


Scala while 循环

和许多语言类似,while 循环在条件为真的时候会持续执行一段代码块。例如,下面的代码在下一个星期五,同时又是13号之前,每天打印一句抱怨的话:

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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 // code-examples/Rounding/while-script.scala  // WARNING: This script runs for a LOOOONG time!  import java.util.Calendar    def isFridayThirteen(cal: Calendar): Boolean =    val dayOfWeek = cal.get(Calendar.DAY_OF_WEEK)     val dayOfMonth = cal.get(Calendar.DAY_OF_MONTH)     // Scala returns the result of the last expression in a method     (dayOfWeek == Calendar.FRIDAY) && (dayOfMonth == 13   while (!isFridayThirteen(Calendar.getInstance())) {      println("Today isn't Friday the 13th. Lame."    // sleep for a day     Thread.sleep(86400000 }

你可以在下面找到一张表,它列举了所有在while 循环中工作的条件操作符。

Scala do-while 循环

和上面的while 循环类似,一个do-while 循环当条件表达式为真时持续执行一些代码。唯一的区别是do-while 循环在运行代码块之后才进行条件检查。要从1 数到10,我们可以这样写:

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1 2 3 4 5 6 // code-examples/Rounding/do-while-script.scala  var count = 0; do    count += 1     println(count)  }while (count < 10);

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