Scala 有几种其它的循环结构,scala几种循环结构
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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//
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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//
code-examples/Rounding/do-while-script.scala
var
count =
0 ;
do
{
count
+ =
1
println(count)
} while
(count < 10 );
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