How do I negate a condition in PowerShell?

Question

How do I negate a conditional test in PowerShell?

For example, if I want to check for the directory C:\Code, I can run:

if (Test-Path C:\Code){   write "it exists!" } 

Is there a way to negate that condition, e.g. (non-working):

if (Not (Test-Path C:\Code)){   write "it doesn't exist!" } 

---

Workaround:

if (Test-Path C:\Code){ } else {   write "it doesn't exist" } 

This works fine, but I'd prefer something inline.

Answer 1

You almost had it with Not. It should be:

if (-Not (Test-Path C:\Code)) {     write "it doesn't exist!" }  

You can also use !: if (!(Test-Path C:\Code)){}

Just for fun, you could also use bitwise exclusive or, though it's not the most readable/understandable method.

if ((test-path C:\code) -bxor 1) {write "it doesn't exist!"} 

Answer 2

If you are like me and dislike the double parenthesis, you can use a function

function not ($cm, $pm) {   if (& $cm $pm) {0} else {1} }  if (not Test-Path C:\Code) {'it does not exist!'} 

Example