Kotlin映射键的顺序保持

fun main() {
    val linkedMap = linkedMapOf(
        "apple" to 1,
        "banana" to 2,
        "cherry" to 3
    )

    for ((key, value) in linkedMap) {
        println("$key -> $value")
    }
}

apple -> 1
banana -> 2
cherry -> 3

fun main() {
    val treeMap = TreeMap<String, Int>()
    treeMap["apple"] = 1
    treeMap["banana"] = 2
    treeMap["cherry"] = 3

    for ((key, value) in treeMap) {
        println("$key -> $value")
    }
}

apple -> 1
banana -> 2
cherry -> 3

fun main() {
    val hashMap = hashMapOf(
        "apple" to 1,
        "banana" to 2,
        "cherry" to 3
    )

    for ((key, value) in hashMap) {
        println("$key -> $value")
    }
}

banana -> 2
cherry -> 3
apple -> 1

fun main() {
    val linkedMap = linkedMapOf(
        "apple" to 1,
        "banana" to 2,
        "cherry" to 3
    )

    for ((key, value) in linkedMap) {
        println("$key -> $value")
    }
}

apple -> 1
banana -> 2
cherry -> 3