1.	val a=1
        val a=”a”
2.	for(i<-arr) println(i)
3.	for(i<-1 to 3;j<-1 to 3 if(i!=j)) println(i*10+j)
4.	val res=for(i<-1 until 10) yield i
        val res=for(i<-1 to 10) yield i
5.	1+2；1+3.3
6.	def test(x: Int, y: Int): Int=x*y
        val f1=(x:Int,y:Int)=>x+y
        def m1(f:(Int,Int)=>Int)=f(3,4)
        m1(f1) 
7.	val f1= m1 _
8.	val arr=new Array[Int](8)
        val arr=Array("java","scala")
        val arr=ArrayBuffer[Int]()
9.	println(arr.toBuffer)
10.	arr+=(2,3,4,5)
11.	arr++=Array(2,3,4,5)
12.	arr2++=ArrayBuffer(8,9,10,11)
13.	arr2.insert(0,0,23)
14.	arr2.remove(1,1)
15.	for(i<-arr3) println(i)
16.	for(i<-0 until arr3.length) println(i)
17.	for(i<-0 until arr3.length) println(arr3(i))
18.	for(i<-(0 until arr3.length).reverse) println(arr3(i))
19.	val res=for(i<-arr3) yield i*10
20.	res.sum  res.max  res.sorted