Question

我有一个数组，需要按索引从中删除项目。由于某种原因，它会复制数组中的其他项目以取代已删除项目的位置。这是一个问题的例子。

import std.stdio: writeln;
import std.algorithm: remove;

void main() {
    string[string] assocArray = [
        "firstvalue": "Number 1",
        "secondvalue": "Number 2",
        "thirdvalue": "Number 3",
        "fourthvalue": "Number 4",
        "fifthvalue": "Number 5",
        "sixthvalue": "Number 6",
    ];

    string[] assocArrayKeys = assocArray.keys(); // I know these aren't in the same order as the literal.

    writeln(assocArrayKeys);
    // ["thirdvalue", "fourthvalue", "fifthvalue", "sixthvalue", "firstvalue", "secondvalue"]

    assocArrayKeys.remove(0);
    assocArrayKeys.remove(5);

    writeln(assocArrayKeys);
    // ["fourthvalue", "fifthvalue", "sixthvalue", "firstvalue", "secondvalue", "secondvalue"]
    // It did remove them, but there are now two "secondvalue"s.
}

任何帮助将不胜感激。

Answer 1

这有点愚蠢。有人指出，在文档中说必须将其重新分配给自己。

请注意，删除不会直接更改原始范围的长度；而是返回缩短的范围。如果未将其返回值分配给原始范围，则原始范围将保留其原始长度，尽管其内容也会更改。

来源：https://dlang.org/library/std/algorithm/mutation/remove.html

解决方案如下：

assocArraykeys = assocArrayKeys.remove(0);
assocArrayKeys = assocArrayKeys.remove(5);

对我来说，这似乎有点愚蠢和不直观，因为它位于std.algorithm.mutation中。关键字：变异。

std.algorithm.remove（）复制数组项？

1 个答案: