Scala-循环

循环

一、循环方法

var list = List("freedom","destiny","fate")
# 循环方法一for
for{
	s <- list
}
println(s)
# 循环方法二for
for{
	s <- list
	if(s.length > 3)
}
println(s)
# 循环方法三for
for(
	s <- list
	if s.length <= 3
)
println(s)
# 循环方法四for
var newList = for{
	s <- list
	s1 = s.toUpperCase
} yield(s1)
for(s <- newList)
println(s)
# 循环方法五while
var i = 0
while(i < list.length){
	println(list(i))
	i += 1
}
# 循环方法六while
var i = 0
do{
	println(list(j))
	j += 1
}while(i < list.length)
# 循环方法七foreach
list.foreach(println)

二、循环例子

（1）判断是否为素数

import util.control.Breaks._
import scala.math._
object Prime {
  def main(args: Array[String]): Unit = {
    var count = 0
    for (prime <- 0 until 100){
      var num : Int = 2
      var flag  = false
      breakable{
        while(num <= sqrt(prime)){
          if(prime % num == 0){
            flag = true
            break()
          }
          num += 1
        }
      }
      if (!flag) count += 1
    }
    println("0到100有"+count+"个素数")
  }
}

（2）判断是否为闰年

object LeapYear {
  def main(args: Array[String]): Unit = {
    var s = 2020
    if ((s % 4 == 0 && s % 100 != 0) || (s % 400 == 0))
      println("2020是闰年")
    else
      println("2020不是闰年")
  }
}