Collection

var/val와 같은 개념 : Mutable, Immutable

1. List

- Immutable

- listOf<자료형>(value1, value2, value3, value4)
- val ages = listOf<Int>(1, 10, 21, 29, 40, 50)

- Mutable

- mutableListOf<자료형>

2. Set (중복을 허용하지 않음)

- Immutable

- setOf<자료형>(value1, value2, value3, value4)
- val ages = setOf<Int>(1, 10, 21, 29, 40, 50)

- Mutable

- mutableSetOf<자료형>

3. Map (key to value 방식)

- Immutable

- mapOf<자료형, 자료형>(key1 to value1, key2 to value2, key3 to value3)
- val ages = setOf<String, Int>("아기" to 1, "초등학생" to 10,"대학생" to 21,"직장인" to 29)

- Mutable

- mutableMapOf<자료형, 자료형>(key1 to value1, key2 to value2, key3 to value3)