Scala学习---数组

 1 /**
 2   * Created by vito on 2017/1/11.
 3   */
 4 object ex1 {
 5   def main(args: Array[String]): Unit = {
 6     //从键盘获得输入
 7     val n = readInt()
 8     val array = new Array[Int](n)
 9     for (i <- 0 until array.length) {
10       array(i) = (new util.Random).nextInt(n)
11     }
12     println(array.mkString(","))
13   }
14 }

 1 /**
 2   * Created by vito on 2017/1/11.
 3   */
 4 object ex2 {
 5   def main(args: Array[String]): Unit = {
 6     val array = Array(1,2,3,4,5)
 7 
 8     //将步进设置为2
 9     for (i <- 0 until (array.length, 2)) {
10       if (i != array.length - 1) {
11         val tmp = array(i)
12         array(i) = array(i + 1)
13         array(i + 1) = tmp
14       }
15     }
16     println(array.mkString(","))
17   }
18 }

 1 /**
 2   * Created by vito on 2017/1/11.
 3   */
 4 object ex3 {
 5   def main(args: Array[String]): Unit = {
 6     val array = Array(1, 2, 3, 4, 5)
 7 
 8     val newArray = for (i <- 0 until(array.length)) yield {
 9       if (i != array.length - 1) {
10         if (i % 2 == 0) array(i + 1) else array(i - 1)
11       } else {
12         array(i)
13       }
14 
15     }
16 
17     println(newArray.mkString(","))
18   }
19 }

 1 /**
 2   * Created by vito on 2017/1/11.
 3   */
 4 object ex5 {
 5   def main(args: Array[String]): Unit = {
 6     val array = Array(1, 2, 3, 4, 5)
 7 
 8     val avg = array.sum / array.length
 9 
10     println(avg)
11   }
12 }