powershell - 当管道整数数组时 $_ 变量为空？

Question

以此为例:

$var = "one","two","three"
0..2 | select-object $var[$_]

Index operation failed; the array index evaluated to null.
At line:1 char:27
+ 0..2 | select-object $var[ <<<< $_]
    + CategoryInfo          : InvalidOperation: (:) [], RuntimeException
    + FullyQualifiedErrorId : NullArrayIndex

为什么 $_ 为空？

Answer 1

我不明白你为什么使用 select-object

试试这个:

$var = "one","two","three"
0..2 | % { $var[$_]}