集合

數組

• 創建數組

new Array[Int](10)

賦值：arr(0) = xxx

? ? ?2.Array[String](“s1”,”s2”,”s3”)

• 數組遍歷

for

foreach

• 創建一維數組和二維數組
• 數組中方法舉例

Array.concate：合并數組

Array.fill(5)(“bjsxt”)：創建初始值的定長數組

• 數組的創建和遍歷?

package com.henu.scala04CollectionAndArrayobject ArrayDemo {def main(args: Array[String]): Unit = {/*** 創建數組兩種方式：* 1.new Array[String](3)* 2.直接Array*///創建類型為Int 長度為3的數組val arr1 = new Array[Int](3)//創建String類型的數組，直接賦值val arr2 = Array[String]("george","love","kangkang")//賦值arr1(0) = 100arr1(1) = 200arr1(2) = 300/*** 遍歷的兩種方式*/for (i <- arr1){println(i)}arr1.foreach(i =>{println(i)})for (s <- arr2){println(s)}arr2.foreach(s =>{println(s)})} }

• 創建二維數組

package com.henu.scala04CollectionAndArrayobject TwoArray {def main(args: Array[String]): Unit = {//創建二維數組val arr = new Array[Array[String]](3)arr(0) = Array("George","love","Sweetie")arr(1) = Array("George","love","Honey")arr(2) = Array("George","love","kangkang")//循環遍歷二維數組for (i <- 0 until arr.length){for (j <- 0 until arr(i).length){print(arr(i)(j) + " ")}println()}var count = 0//創建數組val arr2 = Array[String]("honey","love","george")//輸出二維數組for (a <- arr2; i <- arr2){if (count %3 == 0){println()}print(i + " ")count +=1}println()/*arr2.foreach{ a=>println(a)}for (a <- arr){println(a)}*/arr2.foreach{ a => {a.foreach{println}}}//創建二維數組val arr3 = Array[Array[Int]](Array(1,2,3),Array(4,5,6))//遍歷二維數組arr3.foreach({ a => {a.foreach(i=>{println(i)})}})for (a <- arr3; i <- a){println(i)}} }

• 數組中的方法:

自行查閱API

• 可變長數組

//可變長數組的定義val array = ArrayBuffer[String]("g","e","o")array.append("hello","scala")//在后面追加多個元素array.+=("end")//在最后追加元素array.+=:("Start")//在開頭追加元素arr.foreach(println)for (i <- array){print(i + " ")}

list

• 創建list

val list = List(1,2,3,4)

Nil長度為0的list

• list遍歷

foreach ，for

• list方法舉例

filter:過濾元素

count:計算符合條件的元素個數

map：對元素操作

flatmap ：壓扁扁平,先map再flat

?

package com.henu.Scala05Listobject ListDemo01 {def main(args: Array[String]): Unit = {//創建val list = List(1,2,3,4,5)//遍歷list.foreach{a => println(a)}list.foreach(println)//filterval list1 = list.filter{x => x>3}list1.foreach(println)//countval value = list1.count(x => x>3)println(value)//mapval nameList = List("hello george","hello george","hello george")println("###############################")val mapResult:List[Array[String]] = nameList.map(x => x.split("h"))mapResult.foreach( a =>a.foreach(println))println("###############################")//flatmapval flatMapResult : List[String] = nameList.flatMap( x => x.split(" "))//為了更好理解，將其循環這樣輸出flatMapResult.foreach( a=>a.foreach( i =>{print(i +" ")}))} }

?

• list方法總結

詳情見API? ??https://www.scala-lang.org/api/2.11.12/#scala.collection.immutable.List

• 可變長List

//可變長的listval listBuffer : ListBuffer[Int] = ListBuffer[Int](1,2,3,4,5)listBuffer.append(6,7,8,9)listBuffer.+=(10)//最最后追加元素listBuffer.+=:(100)//在開頭加入元素listBuffer.foreach(println)

?

超強干貨來襲 云風專訪：近40年碼齡，通宵達旦的技術人生

總結

以上是生活随笔為你收集整理的Scala _05集合_数组(一)的全部內容，希望文章能夠幫你解決所遇到的問題。

如果覺得生活随笔網站內容還不錯，歡迎將生活随笔推薦給好友。