scala基础语法-2数组

数组

scala> val arr1 = Array(1,2,3,4,5)arr1: Array[Int] = Array(1, 2, 3, 4, 5)

scala> val arr2 = new Array[Int](5)arr2: Array[Int] = Array(0, 0, 0, 0, 0)

scala> val arr3 = Array[Int](5)arr3: Array[Int] = Array(5)

val arr = Array("hadoop", "spark", "kafka")println(arr(2))> kafka

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可变数组

• 引入mutable下的ArrayBuffer

import scala.collection.mutable.ArrayBufferval arr = new ArrayBuffer[Int]()

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• 添加元素

arr += 1println(arr)> ArrayBuffer(1)

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• 添加元组

arr += (2,3,4,5)println(arr)> ArrayBuffer(1, 2, 3, 4, 5)

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• 添加数组

arr ++= Array(6,7,8)println(arr)> ArrayBuffer(1, 2, 3, 4, 5, 6, 7, 8)

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• 添加可变数组

arr ++= ArrayBuffer(9,10)println(arr)> ArrayBuffer(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)

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• 在index为0的位置插入（5，5，5）

arr.insert(0, 5, 5, 5)println(arr)> ArrayBuffer(5, 5, 5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10)

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• 在index为0的位置删除3个元素

arr.remove(0, 3)println(arr)> ArrayBuffer(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)

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• 排序-sorted

arr += (3,2,4,5,1)println(arr.sorted)println(arr.sorted.reverse)> ArrayBuffer(1, 2, 3, 4, 5)> ArrayBuffer(5, 4, 3, 2, 1)

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• 排序-sortBy

val arr1 = arr.sortBy(x => x)println(arr1)> ArrayBuffer(1, 2, 3, 4, 5)

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• 排序-sortWith

val arr2 = arr.sortWith(_ > _)println(arr2)val arr3 = arr.sortWith(_.compareTo(_) < 0)println(arr3)> ArrayBuffer(5, 4, 3, 2, 1)> ArrayBuffer(1, 2, 3, 4, 5)

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• sum、max、min运算

arr += (1,2,3,4,5)println(arr.sum)println(arr.max)println(arr.min)> 15> 5> 1