1）reverse
2）sortBy
3）filter
val array: Array[Int] = Array(1,2,3,4,5)
val list = List(1,2,3,4)
val map = Map(("a",1),("b",2),("c",3))
val set = Set(1,3,4,5)
val tuple: (Int, Int, Int, Int) = (1,2,3,4)
// 反转
println(list.reverse)
// 排序 : 通过指定的规则来排序
val list1: List[Int] = list.sortBy(num=>num)
println(list1)
val list2: List[Int] = list.sortWith( (x,y)=>{x<y} )
println(list2)
// 过滤
val list3: List[Int] = list.filter((num)=>{num%2==0})
println(list3)
//过滤只留下包含“S”的单词
val wordList = List("Hello", "Hbase", "Hadoop", "Scala", "Spark")
val strings: List[String] = wordList.filter {
(word) => {
word.substring(0, 1).equals("S")
}
}
println(strings)
List(4, 3, 2, 1)
List(1, 2, 3, 4)
List(1, 2, 3, 4)
List(2, 4)
List(Scala, Spark)
