scala中split(“,“) 与 split(“,“,-1)区别

x.split(",") 与 x.split(",",-1)区别

scala> sc.parallelize(List("a,b","a,b,c,","a,b,,,"))

res6: org.apache.spark.rdd.RDD[String] = ParallelCollectionRDD[11] at parallelize at :25

scala> res6.map(x=>x.split(",")).foreach(x=>println(x.toList))

List(a, b)

List(a, b, c)

List(a, b)

scala> res6.map(x=>x.split(",",-1)).foreach(x=>println(x.toList))

List(a, b, , , )

List(a, b, c, )

List(a, b)