Powershell command - null or empty comand is not working

Question

Tried both the cases to check if it is nullorempty but eventhough its null the statement is passing
$RequestorEmail=""

case1
if(($RequestorEmail -ne $null) -or ($RequestorEmail -ne ""))

case2
if ( -not [string]::IsNullOrEmpty( $RequestorEmail ) )

Answer 1

Hi @aditya dugyala ,

maybe this helps:

$a = ""  
if ($a) {   
    Write-Output "variable contains value"   
}  
else {   
    Write-Output "variable is empty"  
}  

Or vice versa:

$a = ""  
if (!$a) {      
    Write-Output "variable is empty"  
}  
else {   
    Write-Output "variable contains value"  
}  

----------

(If the reply was helpful please don't forget to upvote and/or accept as answer, thank you)

Regards
Andreas Baumgarten

Answer 2

In the situation you present, $RequestorEmail contains an empty string.

In your 1st test, since the variable $RequestorEmail is NOT $null (because it holds an empty string), and the string DOES contain an empty string, both conditions fail so the result is FALSE.

In your 2nd test, the variable $RequestorEmail IS empty and the IsNullOrEmpty is true, but you're negating that with the -not operator, so the result is FALSE.

What results where you expecting? And why?