scala元組及拉鍊操做

scala元組及拉鍊操做：

 

scala裏面的元組是但是不一樣數據類型的

scala> ("scala",1)

res45: (String, Int) = (scala,1)

 

scala> val t = ("scala",100L,3.14,("spark",1))

t: (String, Long, Double, (String, Int)) = (scala,100,3.14,(spark,1))

 

scala> t._1                       //元組內空的提取，如下標爲1開始，並用._後跟數字的方式進行提取內容

res46: String = scala

 

scala> t._3

res47: Double = 3.14

 

scala> t._4._1

res48: String = spark

 

scala> val t,(a,b,c,d) = ("scala",100L,3.14,("spark",1))            //能夠定義元組時給予變量名，如 t,(a, b, c, d),使用時直接用變量名a,b,c,d便可訪問對應內容

t: (String, Long, Double, (String, Int)) = (scala,100,3.14,(spark,1))

a: String = scala

b: Long = 100

c: Double = 3.14

d: (String, Int) = (spark,1)

 

scala> a

res49: String = scala

 

scala> val arr = Array(("tingting",1),("ningning",3),("huihui",5))

arr: Array[(String, Int)] = Array((tingting,1), (ningning,3), (huihui,5))

 

scala> val mp = arr.toMap

mp: scala.collection.immutable.Map[String,Int] = Map(tingting -> 1, ningning -> 3, huihui -> 5)

 

scala拉鍊操做：

scala> val arr1 = Array("dog","cat","mouse")

arr1: Array[String] = Array(dog, cat, mouse)

 

scala> val arr2 = Array(1,3,5)

arr2: Array[Int] = Array(1, 3, 5)

 

scala> arr1 zip arr2                     //拉鍊操做符

res50: Array[(String, Int)] = Array((dog,1), (cat,3), (mouse,5))

 

scala> arr2 zip arr1                     //拉鍊操做符

res51: Array[(Int, String)] = Array((1,dog), (3,cat), (5,mouse))

 

scala> arr1.zip(arr2)                     //拉鍊操做符

res52: Array[(String, Int)] = Array((dog,1), (cat,3), (mouse,5))

 

scala> val arr3 = Array(1,2,3,4,5)     //生成一個比arr1元素多的數組，用少的去zip多的

arr3: Array[Int] = Array(1, 2, 3, 4, 5)

 

scala> arr1 zip arr3                      //會把長的給截取掉了

res53: Array[(String, Int)] = Array((dog,1), (cat,2), (mouse,3))