英文:
How to create an Array for Tuples in Scala?
问题
I'm trying to create an empty Array to store coordinates of an object in a Tuple which is then stored in an Array.
When I try:
var walls = Array[Tuple2]()
I'm getting this error message:
kinds of the type arguments (Tuple2) do not conform to the expected kinds of the type parameters (type T).
[error] Tuple2's type parameters do not match type T's expected parameters:
[error] class Tuple2 has two type parameters, but type T has none
[error] var walls = Array[Tuple2]()
Is there any possibility to do this?
英文:
Im trying to create an empty Array to store coordinates of an object in an Tuple which is then stored in an Array.
When I try:
var walls = Array[Tuple2]()
Im getting this error message:
kinds of the type arguments (Tuple2) do not conform to the expected kinds of the type parameters (type T).
[error] Tuple2's type parameters do not match type T's expected parameters:
[error] class Tuple2 has two type parameters, but type T has none
[error] var walls = Array[Tuple2]()
Is there any possibility to do this?
答案1
得分: 4
Tuple2 是一种类型构造器（具有 [*, *] => * 类别）。
Array 也是一种类型构造器（具有 [*] => * 类别）。
要使其能够作为 Array 的参数，您需要将 Tuple2 应用于两种类型（具有 * 类别）。
这就是为什么 Array[(Int, Int)]，也称为 Array[Tuple2[Int, Int]]，有效，而 Array[Tuple2] 则无效的原因。
英文:
Tuple2 is a type constructor (of kind [*, *] => *).
Array is a type constructor too (of kind [*] => *).
You have to apply Tuple2 to two types (of kind *) in order to make it suitable as an argument of Array.
That's why Array[(Int, Int)] aka Array[Tuple2[Int, Int]] is working while Array[Tuple2] is not.
答案2
得分: 2
好的，我找到了一种方法：
var walls = Array<(Int, Int)>()
英文:
Okay I found a way:
var walls = Array[(Int, Int)]()
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