Spark 3000门徒第三课scala高阶函数总结

今晚听了王家林老师3000门徒spark系列课程的第三课，讲述了scala函数，下面写一下心得：

普通函数：def fun1(name:String){println(name)}

函数赋值给变量：val fun1 = functionName _

匿名函数：val fun2 = (name:String) => prinln(name)

高阶函数：def bigData(func:(String) => Unit, content: String){func(content)}

返回值是函数的函数：def func_returned(content:String) = (message:String) => println(content+ " " +message)

curring：def sum_Currying(x:Int) = (y:Int) => x+y

另外课后题：统计一个目录下单词出现的总次数，纯scala来做，下面是我写的代码：

import scala.io.Source
import java.io.File
import scala.collection.mutable

object DirectoryWordCount {

val map = mutable.Map.empty[String, Int]

def wc(file:File) {
if(file.isFile()){
val fileContent = Source.fromFile(file)
for (line <- fileContent.getLines){
line.split(" ").foreach { x =>
if(map.contains(x)) map(x) = map(x)+1
else map(x) = 1
}
}
}
else file.listFiles().foreach(wc)
}

def main(args: Array[String]) {
wc(new File("d:/lian"))
for((key,value) <- map) println(key+":"+value)

}
}