Scala，将二维数组添加到三维数组

Question

我正在尝试将 2d 元素添加到 scala 中的 3d 数组。

我有这 4 个数组 [[]] & [9,2] & [3,1] & [0,9]

我想要 [[9,2],[3,1],[0,9]] < 本质上是将我的 3d 数组转换为 2d 数组的列表。

import Array._

object thing1 {


var list_of_lists = Array():Array[Array[Int]]
var list_1 = Array(9,2)
var list_2 = Array(3,1)
var list_3 = Array(0,9)
println("lllll")
list_of_lists ++ Array(list_1(0),list_1(1));  // nope          although i get an error here saying illegal start of simple expression
list_of_lists ++ list_2;   // nope 
list_of_lists = concat(list_of_lists, list_1) // also nope 
println(list_of_lists(0)(0) + "          this should be 9")
println("lllll")
}

Answer 1

习惯上你可能在寻找类似

的东西

case class Point(x: Int, y: Int)
List(Point(9, 2), Point(3, 2), Point(0, 9))

但是这里有一些使用 Array 的例子：

val list_of_lists = new Array[Array[Int]](3)

val list_1 = Array(9,2)
val list_2 = Array(3,1)
val list_3 = Array(0,9)

list_of_lists(0) = list_1
list_of_lists(1) = list_2
list_of_lists(2) = list_3

assert(list_of_lists(0)(0) == 9)

或

val list_1 = Array(9,2)
val list_2 = Array(3,1)
val list_3 = Array(0,9)
assert(Array(list_1, list_2, list_3).apply(0)(0) == 9)

或

val list_1 = Array(9,2)
val list_2 = Array(3,1)
val list_3 = Array(0,9)
assert((Array[Array[Int]]() :+ list_1 :+ list_2 :+ list_3).apply(0)(0) == 9)

Scala，将二维数组添加到三维数组

Scala, Adding 2d arrays to a 3d array

arrays

scala

concat