第五章_Spark核心编程_Rdd_行动算子_count

1.定义

  /*
* 1.定义
*     def count(): Long
* 2.功能
*     返回 RDD 中元素的个数
*
* */

2. 示例

  object countTest extends App {

    val sparkconf: SparkConf = new SparkConf().setMaster("local").setAppName("distinctTest")

    val sc: SparkContext = new SparkContext(sparkconf)

    private val rdd: RDD[Int] = sc.makeRDD(List(8, 2, 4, 2), 4)

    private val result = rdd.count()

    println(result)

    sc.stop()
  }