补5

1.1

object base21 {
  def main(args: Array[String]): Unit = {
    var sum = 0
    var i = 1
    while(i<=100){
      println(i)
      sum = sum +i
       i +=1
    }
    println(sum)
  }
}

1.2

object base22 {
  def main(args: Array[String]): Unit = {
  //do while: 无论条件是否成立，都会执行一次！
  // while: 如果条件不成立，不会执行！
  // var i = 100
  // do {
  // println(i)
  // i += 1
  // } while(i<=10)
  var i = 100
    while(i<=10){
      println(i)
      i += 1
    }
  }
}

1.3 scala object base23 { def main (args: Array [String]): Unit = { }// 求 1 - 1/2 + 1/3 - 1/4 + 1/5 -.... + 1/19 的和 var sum: Double = 0 var i = 1 while (i <= 100) { if (i % 2 == 1) { sum = sum + 1.0 /i/ 1/3 } else { sum = sum - 1.0 /i/ 1/2

i += 1 } println (s"sum=${sum}") } }