大数据Spark “蘑菇云”行动前传第5课：零基础实战Scala函数式编程及Spark源码解析

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大数据Spark “蘑菇云”行动前传第5课：零基础实战Scala函数式编程及Spark源码解析
1 spark中scala集合操作鉴赏
2 scala集合操作实战

  val array= new Array[Int](5)
    array(0) =10
    array(5)=1

Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 5
at com.dt.spark.scala.bascis.HelloArray$.main(HelloArray.scala:8)
at com.dt.spark.scala.bascis.HelloArray.main(HelloArray.scala)

package com.dt.spark.scala.bascis

object HelloArray {
def main(args: Array[String]): Unit = {

    val array= new Array[Int](5)
    array(0) =10

    val array2 = Array[Int](1,2,3,4,5)
    val array3 = Array.apply(1,2,3,4,5)

    for (imfitem <- array ) println(imfitem)


    val name = Array("scala","spark")
    for(item<- name) println(item)

    import scala.collection.mutable.ArrayBuffer
    val arrayBuffer = ArrayBuffer[Int]()

    arrayBuffer +=1
    arrayBuffer +=2
    arrayBuffer +=(4,5,6,7,8,9,10)
    arrayBuffer ++= Array (1,2,3,4,5)
    arrayBuffer.insert(arrayBuffer.length-1, 100,1000)

    arrayBuffer.remove(arrayBuffer.length-1)
    arrayBuffer.toArray

    for(item<- arrayBuffer) println(item)


    for(imf <- (0 until array.length).reverse) println(imf)


    scala.util.Sorting.quickSort(array)
    println ("===    " + array.mkString(","))

   val arrayAdded100 =   for ( item <- array) yield item +100
    println (arrayAdded100.mkString(" "))


    val arrayEven =for ( item <- array if item % 2 == 0) yield item
    println (arrayEven.mkString(","))

     println (array.filter { x => x % 2 == 0 }.mkString(","))


}
}

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