# 컬렉션

- listOf()

- setOf()

- mapOf()

- mutableListOf()

- mutableSetOf()

- mutableMapOf()


```kotlin
val numberSet = setOf("one", "two", "three")
val emptySet = mutableSetOf<String>()
```

```kotlin
val numberMap = mapOf("one" to 1, "two" to 2, "three" to 3)
```

## 빌더 함수

- buildList()

- buildSet()

- buildMap()


```kotlin
val map = buildMap{
    put("a", 1)
    put("b", 2)
}
```

## 빈 컬렉션

- emptyList()

- emptySet()

- emptyMap()


```kotlin
val empty = emptyList<String>()
```

## 복제

- toList()

- toMutableList()

- toSet()