scala作业1

1.
//当i=10时候终止运行，跳出循环
object homework {
  def main(args: Array[String]): Unit = {
    var flag=false//这里变量修饰必须是var
    for(i <-1 to 20 if(!flag))
      {
        println(i)
        if(i==10)
          flag=true
      }
  }
}
结果：
1
2
3
4
5
6
7
8
9
10
2.

object homework {
  def main(args: Array[String]): Unit = {
    var t: Long = 1
    val str: String = "Hello"
    for (ch <- str) {
      t = t * ch
    }
    println(t)
  }

}
结果：9415087488

3.
object homework {
  def product(str:String):Long={
    var t:Long=1
    for (ch <-str)
      {
        t=t*ch
      }
    t
  }
  def main(args: Array[String]): Unit = {
    print(product("Hello"))
  }
}
结果：9415087488

4.

object homework {
  def revert(a:Array[Int]) = {
    for(i <- 0 until (a.length - 1,2)){
      val temp = a(i)
      a(i) = a(i+1)
      a(i+1) = temp
    }
  }
  def main(args: Array[String]): Unit = {
    val arr=Array(2,3,4,1,5,6,0,9)
    revert(arr)
    println(arr.toBuffer)
  }
}
结果：ArrayBuffer(3, 2, 1, 4, 6, 5, 9, 0)