回答編集履歴
2
ループのたびにmapを呼ぶのは非効率なので修正
answer
CHANGED
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@@ -8,5 +8,6 @@
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8
8
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もちろん、filterNot+containsで書くこともできます。その場合はこんな感じで
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9
9
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10
10
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```kotlin
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11
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+
val listCodes = dbList.map { it.divisionCode }
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11
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-
val uncontainedKeys = rawMap.keys.filterNot
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12
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+
val uncontainedKeys = rawMap.keys.filterNot(listCodes::contains)
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12
13
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```
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1
質問に合わせてコード修正
answer
CHANGED
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@@ -2,11 +2,11 @@
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2
2
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[リファレンス](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin.collections/minus.html)
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3
3
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4
4
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```kotlin
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5
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-
val uncontainedKeys = rawMap.keys -
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5
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+
val uncontainedKeys = rawMap.keys - dbList.map { it.divisionCode }
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6
6
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```
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7
7
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8
8
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もちろん、filterNot+containsで書くこともできます。その場合はこんな感じで
|
|
9
9
|
|
|
10
10
|
```kotlin
|
|
11
|
-
val uncontainedKeys = rawMap.keys.filterNot
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11
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+
val uncontainedKeys = rawMap.keys.filterNot { dbList.map { it.divisionCode }.contains(it) }
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12
12
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```
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