使用Scala生成随机数的方法示例

/*
1.you can use scala.util.Random.nextInt(10) to produce a number between 1 and 10
2.at the same time,you nextInt(100) to produce a number between 1 and 100
*/
object Test {
 def main(args: Array[String]) {
  var i = 0
  while(i < 10)
   var str = scala.util.Random.nextInt(100).toString
   println(str)
   i = i+1
  }
 }
}

object Test{
 def main(args: Array[String]): Unit = {
  val wordPerMessage = 4
  var i = 0
  while(i<10){
   /*
   1.the (1 to 1) is meaning that only have one circulation.
   */
   (1 to 1).foreach { messageNum => {
    //[There's only three cycle]
    val str: Seq[String] = (1 to wordPerMessage).map(x => scala.util.Random.nextInt(10).toString)
    val str1 = str.mkString(" ")//separate str1 with space
    println(str)
    }
   }
   i = i +1
  }
 }
}

def randomNew(n:Int)={
 var resultList:List[Int]=Nil
 while(resultList.length<n){
  val randomNum=(new Random).nextInt(20)
  if(!resultList.exists(s=>s==randomNum)){
   resultList=resultList:::List(randomNum)
  }
 }
 resultList
}

def randomNew2(n:Int)={
 var arr= 0 to 20 toArray
 var outList:List[Int]=Nil
 var border=arr.length//随机数范围
 for(i<-0 to n-1){//生成n个数
  val index=(new Random).nextInt(border)
  println(index)
  outList=outList:::List(arr(index))
  arr(index)=arr.last//将最后一个元素换到刚取走的位置
  arr=arr.dropRight(1)//去除最后一个元素
  border-=1
 }
 outList
}