When should I use Write-Error vs. Throw? Terminating vs. non-terminating errors

Question

Looking at a Get-WebFile script over on PoshCode, http://poshcode.org/3226, I noticed this strange-to-me contraption:

$URL_Format_Error = [string]\"...\"
Wri         


        

Answer 1

Addition to Andy Arismendi's answer:

Whether Write-Error terminates the process or not depends on the $ErrorActionPreference setting.

For non-trivial scripts, $ErrorActionPreference = "Stop" is a recommended setting to fail fast.

"PowerShell’s default behaviour with respect to errors, which is to continue on error ...feels very VB6 “On Error Resume Next”-ish"

(from http://codebetter.com/jameskovacs/2010/02/25/the-exec-problem/)

However, it makes Write-Error calls terminating.

To use Write-Error as a non-terminating command regardless of other environment settings, you can use common parameter -ErrorAction with value Continue:

 Write-Error "Error Message" -ErrorAction:Continue