Powershell-else in try/catch - powershell

Question

I'm trying to write output when get-addomain succeded.
Try/catch writes output only if command fails
try {
get-addomain -Identity d.contoso.com
}
catch {
Write-Output "failed"
}
I tried following:
if (-not (get-addomain -Identity d.contoso.com))
{
return "failed"
}
else
{
write-output "ok"
}
and
If (get-addomain -Identity d.contoso.com )
{
Write-Output "ok"
}
Else
{
write-output "failed"
}
but in both cases got
get-addomain : Cannot find an object with identity: 'd.contoso.com' under: 'DC=ad,DC=contoso,DC=com'.

Answer 1

The tryblock runs until a error is getting thrown. If get-addomain doesn't end with an error, the try-case will run the following commands written inside the {}.
So one way would be to just say the output is ok if no error gets thrown:
try {
get-addomain -Identity d.contoso.com
Write-Output "ok"
}
catch {
Write-Output "failed"
}
But if you want to double check, you can still do the if check in the try-catch:
try {
If (get-addomain -Identity d.contoso.com )
{
Write-Output "ok"
}
Else
{
write-output "failed"
}
}
catch {
Write-Output "failed"
}

Answer 2

try{
$domain = Get-ADDomain -Identity d.contoso.com
Write-Output $domain
}catch{
Write-Output "Failed with message '$($_.Exception.Message)'"
}
When you use the AD CmdLets, it fails when a non-existing identity is specified. Therefore if the object you search for does not exist, you will end up in the catch. The first piece of code you wrote is actually correct if you wish to output the AD domain information.