Powershell Output (“echo”) a variable to a text file

https://stackoverflow.com/questions/19122755/output-echo-a-variable-to-a-text-file

After some trial and error, I found that

$computername = $env:computername

works to get a computer name, but sending $computername to a file via Add-Content doesn't work.

I also tried $computername.Value.

Instead, if I use

$computername = get-content env:computername

I can send it to a text file using

$computername | Out-File $file