Kotlin Documentation | Write operations

Kotlin Documentation 시리즈에 대해

Category: Standard library - Collections

문서 링크: https://kotlinlang.org/docs/collection-write.html

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Adding elements

• add(), addAll()
• +=

val numbers = mutableListOf("one", "two")
numbers += "three"
println(numbers)
numbers += listOf("four", "five")    
println(numbers)

Removing elements

• remove(), removeAll()
• retainAll(): removeAll()의 반대. 주어진 컬렉션만을 남긴다.
• clear()
• -=

val numbers = mutableListOf("one", "two", "three", "three", "four")
numbers -= "three"
println(numbers)
numbers -= listOf("four", "five")    
//numbers -= listOf("four")    // does the same as above
println(numbers)

[one, two, three, four]
[one, two, three]