33rd: List of the first-order function operation code to combat the detailed

The parameter of the operation is not a function, it is the first order function

We use specific code to illustrate:

Package com.dt.scala.datasetobject listfirstorderops {  def main (args:  Array[string]):  unit = {    //list Merge, using::: operator &NBSP;&NBSP;&NBSP;&NBSP;PRINTLN ( List::: List (3,4)::: List (5,6))     println (list):::(list (3,4)::: List (5,6)))      //  the length of the list     println (list (1,2,3,4,5,5). Length)      val bigdata = list ("Spark", "Hadoop", "Kafka")     //the last element of the list      println (bigdata.last)  //kafka    //selects all elements except the last element      println (Bigdata.init)  //list (spark, hadoop)     //reverses the position of elements in the list      println (Bigdata.reverse)  //list (Kafka, hadoop, spark)      Take the first n elements     println (Bigdata.take (2))     //take all the elements except the first n      println (Bigdata.drop (2)     //  split list to two list at n position. The effect is equivalent to (c take n,c drop n)   But Splitat is more efficient     println (bigData.splitAt ( 2)  //(list (spark, hadoop), List (Kafka))     //The value of the element by index, and the index starts with 0 . Execution requires time index values to be proportional.     println (Bigdata.apply (2))  //kafka    println (BigData (2))  //  actually calls the Apply method         val data = list ("a" , "B", "C", "D", "E", "F", "G")     //produce a range    println with the index of the list (data.indices )  //range (0, 1, 2, 3, 4, 5, 6)     //zip operation with index and data, This operation is called the zipper Operation     println (Data.indices zip data)  //vector ((0,a),  (1,b),   (2,c),  (3,d),  (4,e),  (5,f),  (6,g))     //  list provides a way to implement the above zipper operation     println (Data.zipwithindex)     //Convert list to String     println (Data.tostring ())  //"list (a, b, c, d, e,  F,&NBSP;G) "    //uses strings to stitch together elements in the list     println (data.mkstring (" < ",   ",",  ">")  //"<a,b,c,d,e,f,g>"     println (data.mkstring (","))  //"A,b,c,d,e,f,g"     println (data.mkstring)  //"ABCDEFG"              val buffer = new StringBuilder     //Append all elements of the list to the StringBuilder object     data.addstring (buffer)      //  with Data.mkstring ("<",  ",",  ">") this operation type, except that addstring will append the string     / /To StringBuilder object     data.addstring (buffer,  "<",  ",",  ">")   &NBSP;&NBSP;&NBSP;PRINTLN (buffer)         //array and list mutual transfer         &nbsP;val arr = data.toarray    println (arr.tolist)          //Get iterators     val iterator = data.iterator     println (Iterator.next ())     println (Iterator.next ())        }}

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33rd: List of the first-order function operation code to combat the detailed