PowerShell的特殊数组头/尾分配在哪里记录？ [英] Where is PowerShell's special array head/tail assignment documented?

问题描述

我只是注意到这是有效的PowerShell代码：

I only just noticed that this is valid PowerShell code:

PS> $first, $rest = @(1, 2, 3)

此语句将第一个项目放入在 $ first 中的数组和在 $ rest 中的其余项。

This statement puts the first item in the array in $first and the remaining items in $rest.

PS> $first
1

PS> $rest
2
3

它甚至适用于任意数量的变量，将当前标题推入下一个变量，将尾标推入最后一个变量。您可以自己尝试。

It even works for an arbitrary number of variables, pushing the current head into the next variable and the tail into the last one. You can try that for yourself.

PS> $first, $second, $rest = @(1, 2, 3, 4)

如果没有足够的开头或结尾放入变量之一，则分配 $ null 值。即使在 $ rest 的情况下（我宁愿看到一个空数组，但无论如何）。

It seems to assign a $null value if there aren't enough heads or tails to put into one of the variables. Even in the case of the $rest (I'd rather have seen an empty array, but whatever).

PS> $first, $second, $rest = @(1)

PS> $first
1

PS> $second

PS> $second -eq $null
True

PS> $rest

PS> $rest -eq $null
True

PS> $rest -eq @()
False

问题和我的问题是我在任何地方都看不到此文件！我正在尝试找出何时支持。确切的实施方式。如果它适用于任何其他类型。

The problem, and my question, is that I don't see this documented anywhere! I'm trying to find out when this was supported. Exactly how it's implemented. If it works for any other types.

我检查了 about_Assignment ， about_Arrays 和 about_Splatting ，没有任何运气。

I checked about_Assignment, about_Arrays, and about_Splatting, without any luck.

推荐答案

请参阅底部附近的分配多个变量部分。 about_Assignment_Operators 。

See the section ASSIGNING MULTIPLE VARIABLES near the bottom of about_Assignment_Operators.

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