Scala's classic 82nd: How does the listbuffer of the list in Scala implement efficient traversal calculations?

Package Com.dt.scala.list

Object Listbuffer_internals {

def main (args:array[string]) {

Val list = list (1,2,3,4,5,6,7,8,9)

Increment (list)

Increment_moreeffective (list)

Increment_mosteffective (list)

}

def increment (List:list[int]): list[int] = list match {

Case list () = List ()

Case HEAD:: tail = head + 1:: Increment (tail)

}

def increment_moreeffective (List:list[int]): list[int] = {

var result = List[int] ()

for (element <-list) result = Result::: List (element + 1)

Result

}

def increment_mosteffective (List:list[int]): list[int] = {

Import Scala.collection.mutable.ListBuffer

var buffer = new Listbuffer[int]

for (element <-list) Buffer + = element + 1

Buffer.tolist

}

}

3 ways:

1. Stacks that generate too many function calls
2. Many intermediate results have been produced
3. Optimal

Information from DT Big Data Dream Factory, public number: Dt_spark
Video address:http://edu.51cto.com/lesson/id-71305.html

Scala's classic 82nd: How does the listbuffer of the list in Scala implement efficient traversal calculations?