heroherotail score 14
2017/02/08 17:47 投稿
| Kotlin(Java?)でのArrayListへの要素の追加についての質問です |
| 実行環境はKotlin ver1.0.6でJava8です |
| ArrayListを使い，要素の追加・取り出しを行いたいのですが |
| うまくいきません |
| for文の中でmodelをModelFactory#createModelから作成し， |
| ArrayListであるmodelsにaddしているのですが，新しく作成したmodelが |
| 既に入っている要素を全て塗りつぶしてしまう結果となります． |
| 以下が実装です |
| ###ソースコード |
| ```Kotlin |
| fun main(args: Array<String>){ |
| val models: ArrayList<Model> = ArrayList() |
| for (i in 0..4){ |
| val model = ModelFactory().createModel() |
| models.add(model) |
| for (m in models) |
| println("i,x,y = " + (i+1).toString() + "," + m.x.toString() + "," + m.y.toString()) |
| } |
| for (model in models) |
| println("x,y = " + model.x.toString() + "," + model.y.toString()) |
| } |
| ``` |
| ### 結果 |
| ``` |
| i,x,y = 1,0.07473496472821772,0.30797528302849175 |
| i,x,y = 2,0.6254996345471039,0.2674472108375042 |
| i,x,y = 2,0.6254996345471039,0.2674472108375042 |
| i,x,y = 3,0.927361187034477,0.8790114619475532 |
| i,x,y = 3,0.927361187034477,0.8790114619475532 |
| i,x,y = 3,0.927361187034477,0.8790114619475532 |
| i,x,y = 4,0.32678477794185257,0.33446341578663796 |
| i,x,y = 4,0.32678477794185257,0.33446341578663796 |
| i,x,y = 4,0.32678477794185257,0.33446341578663796 |
| i,x,y = 4,0.32678477794185257,0.33446341578663796 |
| i,x,y = 5,0.1805648560841221,0.8108814141273503 |
| i,x,y = 5,0.1805648560841221,0.8108814141273503 |
| i,x,y = 5,0.1805648560841221,0.8108814141273503 |
| i,x,y = 5,0.1805648560841221,0.8108814141273503 |
| i,x,y = 5,0.1805648560841221,0.8108814141273503 |
| x,y = 0.1805648560841221,0.8108814141273503 |
| x,y = 0.1805648560841221,0.8108814141273503 |
| x,y = 0.1805648560841221,0.8108814141273503 |
| x,y = 0.1805648560841221,0.8108814141273503 |
| x,y = 0.1805648560841221,0.8108814141273503 |
| ``` |
| 素人考えで直接的な関係はないと思いますが，実行に使ったクラスです |
| ```Kotlin |
| class Model (var x: Double, var y: Double){ |
| companion object{ |
| val CREATOR = Model(0.0,0.0) |
| } |
| } |
| ``` |
| ```Kotlin |
| class Logic { |
| companion object{ |
| fun customize(model: Model): Model { |
| var random = Random() |
| model.x = random.nextDouble() |
| model.y = random.nextDouble() |
| return model |
| } |
| } |
| } |
| ``` |
| ```Kotlin |
| class ModelFactory { |
| fun createModel(): Model { |
| val model = Logic.customize(Model.CREATOR) |
| return model |
| } |
| } |
| ``` |
| ###アドバイスを受けて |
| Modelクラスを以下のように変更した結果，期待通りの動きを得ることが出来ました |
| ```Kotlin |
| class Model (var x: Double, var y: Double) |
| ``` |
