Mastering Windows PowerShell Scripting - Third Edition

Re-throwing errors

An error might be re-thrown within a catch block. This technique can be useful if a try block performs a number of dependent steps in a sequence where one or more might fail.

Re-throwing an error raised by a script can be as simple as using throw in a catch block:

try { 
    'Statement1' 
    throw 'Statement2' 
    'Statement3' 
} catch { 
    throw 
} 

ThrowTerminatingError might be used instead, depending on the desired behavior:

function Invoke-Something { 
    [CmdletBinding()] 
    param ( )     try { 
        'Statement1' 
        throw 'Statement2' 
        'Statement3' 
    } catch { 
        $pscmdlet.ThrowTerminatingError($_) 
    } 
} 

When an error is re-thrown in this manner, the second instance of the error (within the catch block) is not written to either Error or an error variable. In ...