scala函数例子

/**
* Created by 向超 on 2017/5/31.
*/
object scalaFunc {
def main(args: Array[String]): Unit = {
def fun(str1:String,str2:String)={
str1+”\t”+str2
}
println(fun(“hadoop”,”spark”))

def add=(str1:String,str2:String)=>str1+"\t"+str2
println(add("hadoop","spark"))

def g(f:(String,String)=>String,str1:String,str2:String)={
  val line = f(str1,str2)
  println(line)
}
g(add,"hadoop","spark")

val list = List.range(1,10)
println(list.mkString("[","\t","]"))
val list2 = list.filter((x:Int)=>x%2==0)
println(list2.mkString("[","\t","]"))

val list3 = list.filter(x=>x%2==0)
println(list3.mkString("[","\t","]"))

val list4 = list.filter(_%2==0)
println(list4.mkString("[","\t","]"))

val sayHello:()=>Unit = () =>println("hello")

def g1(f:()=>Unit,num:Int)={
  for(i<-1 to num)f()
}
g1(sayHello,5)

def saySomething(str1:String)=(str2:String)=>println(str1+"\t"+str2)

val aa:String=>Unit=saySomething("spark")

aa("hadoop")


var standardAge = 20
val aa1 = (age:Int)=>age>=standardAge
println(aa1(22))

def g2(f:Int=>Boolean,age:Int):Unit={
  println(f(age))
}
g2(aa1,22)
standardAge = 23
g2(aa1,22)

var more = 10
val x=(one:Int)=>one+more
println(x(20))
more=20
println(x(20))

var sum = 0
val array = Array(10,20,30)
array.foreach(f=>sum=sum+f)
println(sum)

}
}

输出结果：
hadoop spark
hadoop spark
hadoop spark
[1 2 3 4 5 6 7 8 9]
[2 4 6 8]
[2 4 6 8]
[2 4 6 8]
hello
hello
hello
hello
hello
spark hadoop
true
true
false
30
40
60