在kotlin中，除了map的entrySet和stream的使用之外，还有什么替代方案？

val map = mapOf("a" to 1, "b" to 2, "c" to 3)
map.forEach { (key, value) ->
    println("Key: $key, Value: $value")
}

val map = mapOf("a" to 1, "b" to 2, "c" to 3)
for ((key, value) in map) {
    println("Key: $key, Value: $value")
}

val list = listOf("a", "b", "c")
val map = list.associateWith { it.length }
println(map) // 输出: {a=1, b=1, c=1}

val list = listOf("apple", "banana", "apricot", "blueberry")
val map = list.groupBy { it.first() }
println(map) // 输出: {a=[apple, apricot], b=[banana, blueberry]}

val map = mapOf("a" to 1, "b" to 2, "c" to 3)
val newMap = map.mapValues { (_, value) -> value * 2 }
println(newMap) // 输出: {a=2, b=4, c=6}

val list = listOf(1, 2, 3, 4, 5)
val result = list.filter { it % 2 == 0 }.map { it * 2 }
println(result) // 输出: [4, 8]

val list = listOf(1, 2, 3, 4, 5)
val sum = list.reduce { acc, value -> acc + value }
println(sum) // 输出: 15

val product = list.fold(1) { acc, value -> acc * value }
println(product) // 输出: 120