反转字符串
$a="asdfghjklqwe"
$b=$null
foreach ($_ in ("$a".length-1)..0)
{
$b +=$a[$_]
}
$b
$a="asdfghjklqwe"
$b = $a.ToCharArray()
[array]::Reverse($b)
$b -join ''
[array]静态类属性：
$a="asdfghjklqwe"
$b=$null
foreach ($_ in ("$a".length-1)..0)
{
$b +=$a[$_]
}
$b
$a="asdfghjklqwe"
$b = $a.ToCharArray()
[array]::Reverse($b)
$b -join ''
[array]静态类属性：
