如何在Kotlin中复制二维数组? [英] How to copy a two-dimensional array in Kotlin?

问题描述

此方法可以正常工作.但是，我认为它不起作用.

This method works fine. However, I think it is not functional.

fun getCopy(array: Array<BooleanArray>): Array<BooleanArray> {
    val copy = Array(array.size) { BooleanArray(array[0].size) { false } }
    for (i in array.indices) {
        for (j in array[i].indices) {
            copy[i][j] = array[i][j]
        }
    }
    return copy
}

还有更实用的方法吗?

推荐答案

您可以使用 clone 就像这样:

You can make use of clone like so:

fun Array<BooleanArray>.copy() = map { it.clone() }.toTypedArray()

或者如果您想保存一些分配:

or if you'd like to save some allocations:

fun Array<BooleanArray>.copy() = arrayOfNulls<ByteArray>(size).let { copy ->
    forEachIndexed { i, bytes -> copy[i] = bytes.clone() }
    copy
} as Array<BooleanArray>

或更简洁，如 @hotkey 所建议:

fun Array<BooleanArray>.copy() = Array(size) { get(it).clone() }

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