Powershell For-Loop throws MissingVariableNameAfterForeach - powershell

Question

Why do I get the error "MissingVariableNameAfterForeach" for the following:
powershell.exe -NoProfile -ExecutionPolicy Bypass -Command "foreach($file in Get-ChildItem C:){((Get-Date)-$file.LastWriteTime).ToString('dd')}"
The command is supposed to print out the day since today of the last file/folder write in C:\

Answer 1

From the help text:
PS C:\> powershell.exe /?
If the value of Command is a script block, the script block must be enclosed
in braces ({}). You can specify a script block only when running PowerShell.exe
in Windows PowerShell.
Try this:
powershell.exe -NoProfile -ExecutionPolicy Bypass -Command {Get-ChildItem C: | ForEach-Object{($_.LastWriteTime).ToString('dd')}}

Answer 2

Your command will work if you enclose the Get-ChildItem in parentheses.
powershell.exe -NoProfile -ExecutionPolicy Bypass -Command ^
"foreach($file in (Get-ChildItem C:)){((Get-Date)-$file.LastWriteTime).ToString('dd')}"

Answer 3

I may have understood your question, because the existing answers do not seem to provide the information I thought you were looking for.
Whilst these examples don't specifically answer the question posed in your title, they are intended to output what I think you were looking for.
Here therefore is my batch-file attempt:
#"%__AppDir__%WindowsPowerShell\v1.0\powershell.exe" -NoProfile -Command^
"Get-ChildItem -Path 'C:\'|Sort-Object -Property LastWriteTime|"^
"Select-Object -Last 1|Format-Table -AutoSize -Property Name,"^
"#{Name='DaysOld';Expression={[Int]$((Get-Date)-$_.LastWriteTime).TotalDays}}"
#Pause
And obviously the cmd version, to be on topic:
"%__AppDir__%WindowsPowerShell\v1.0\powershell.exe" -NoProfile -Command "Get-ChildItem -Path 'C:\'|Sort-Object -Property LastWriteTime|Select-Object -Last 1|Format-Table -AutoSize -Property Name,#{Name='DaysOld';Expression={[Int]$((Get-Date)-$_.LastWriteTime).TotalDays}}"
Just in case it is simply my misunderstanding, perhaps this batch-file may work for you:
#"%__AppDir__%WindowsPowerShell\v1.0\powershell.exe" -NoProfile -Command^
"Get-ChildItem -Path 'C:\'|Sort-Object -Property LastWriteTime -Descending|"^
"Format-Table -AutoSize -Property Name,"^
"#{Name='DayInMonth';Expression={($_.LastWriteTime).ToString('dd')}},"^
"#{Name='DaysOld';Expression={[Int]$((Get-Date)-$_.LastWriteTime).TotalDays}}"
#Pause
cmd version:
"%__AppDir__%WindowsPowerShell\v1.0\powershell.exe" -NoProfile -Command "Get-ChildItem -Path 'C:\'|Sort-Object -Property LastWriteTime -Descending|Format-Table -AutoSize -Property Name,#{Name='DayInMonth';Expression={($_.LastWriteTime).ToString('dd')}},#{Name='DaysOld';Expression={[Int]$((Get-Date)-$_.LastWriteTime).TotalDays}}"
In both cases, you'll note because I'm not running a PowerShell script, there is no need to stipulate an execution policy. Commands should work as if being run directly in the PowerShell window.