2024-06-21

Writerside/topics/Enum.md

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+# 열거형
+
+```kotlin
+enum class Direction {
+    NORTH, SOUTH, EAST, WEST
+}
+
+enum class Color(val rgb: Int) {
+    RED(0xff0000),
+    GREEN(0x00ff00),
+    BLUE(0x0000ff)
+}
+```
+
+```kotlin
+val dir = Direction.valueOf("NORTH")
+for (item in Direction.values()) {
+    // ...
+}
+```
+
+## 익명 클래스
+
+```kotlin
+enum class State {
+    WAITING {
+        override fun signal() = TALKING
+    },
+    TALKING {
+        override fun signal() = WAITING
+    }
+
+    abstract fun signal(): State
+}
+```
+
+## 인터페이스
+
+```kotlin
+enum class IntArithmetics : BinaryOperator<Int>, IntBinaryOperator {
+    PLUS {
+        override fun apply(t: Int, u: Int): Int = t + u
+    },
+    TIMES {
+        override fun apply(t: Int, u: Int): Int = t * u
+    };
+
+    override fun applyAsInt(t: Int, u: Int) = apply(t, u)
+}
+```