why does this not evaluate to 6

[Shane Participant Topics: 25 Replies: 39 Points: 50Rank: Member]

$x = 5
$y = $x++
write-host $y

why is $y evaluating to  5 and not 6?

[kvprasoon]

$x++ doesn’t return anything, instead it increments variable x’s value by 1. If you wan’t it to return, just wrap it in parenthesis.

$y = ($x++)

• This reply was modified 3 months, 1 week ago by kvprasoon. Reason: post correction

[Shane]

I did try that also and it is still evaluates to 5

 

• This reply was modified 3 months, 1 week ago by Shane.

[Kiran]

It should work, it is called Variable Squeezing in PowerShell.

And as kvprasoon mentioned, $x++ will not return any value, it is used for self increment, so it can’t be assigned to $y.

Either you can use $y = $x + 1 or $y = ($x++)

Thank you.

• This reply was modified 3 months, 1 week ago by Kiran. Reason: Spelling correction

[Shane]

Thank you for your help

I suspect I am doing something wrong or missing something obvious. I opened up a new shell and type the following:

PS C:\Users\superuser> $x = 5
PS C:\Users\superuser> $x
5
PS C:\Users\superuser> $y = ($x++)
PS C:\Users\superuser> $y
5

 

• This reply was modified 3 months, 1 week ago by Shane.

[Kiran Moderator Topics: 3 Replies: 222 Points: 1,206Rank: Community Hero]

Okay, what is your windows? is it Server edition or Client Edition?

I think variable squeezing won’t work in Server side PowerShell.

[Olaf Participant Topics: 4 Replies: 2249 Points: 5,494Rank: Community MVP]

@Kiran does it really work for you on your systems? I checked it on my client W10 1909, Windows Powershell 5.1 or Powershell 7.0.0-rc.3. The result is the same on both versions.

PS C:\> $x = 5
PS C:\> $x
5
PS C:\> $y = ($x++)
PS C:\> $y
5

[Kiran]

[Edit]

Yes, I checked it on my Windows 10 1909 (itself) and it is working on Windows PowerShell 5.1, PowerShell Core 6.2.3 and PowerShell 7 rc3 as well  and not on 6.2.3 & 7.0.0-rc3 (sorry for the little confusion)

But not working on Window Server 2019 with Windows PowerShell 5.1

 

• This reply was modified 3 months, 1 week ago by Kiran. Reason: Correction

[Shane]

Mine is Windows 10 pro 1903, running powershell 5.1.

• This reply was modified 3 months, 1 week ago by Shane.

[Shane Participant Topics: 25 Replies: 39 Points: 50Rank: Member]

Kiran wrote:

Yes, I checked it on my Windows 10 1909 (itself) and it is working on Windows PowerShell 5.1, PowerShell Core 6.2.3 and PowerShell 7 rc3 as well

But not working on Window Server 2019 with Windows PowerShell 5.1

interesting. Thanks

[Kiran]

I have double checked and noticed the below…

	Win PS 5.1		PS Core 6.2.3	PS 7.0.0-rc3
Windows	Native Console	Windows Terminal (Preview)	Native Console	Windows Terminal (Preview)	Native Console	Windows Terminal (Preview)
Windows 10 1909	YES	NO	NO	NO	NO	NO
Windows Server 2019	NO

It looks very weird behavior.

• This reply was modified 3 months, 1 week ago by Kiran.

[js]

++ after the variable increments after sending the value, ++ before the variable increments before sending the value.

$x = 5
$y = ++$x
$y

6

There’s a similar thing in bash (or C):

x=5
y=$((++x))
echo $y

6

• This reply was modified 3 months, 1 week ago by js.
• This reply was modified 3 months, 1 week ago by js.
• This reply was modified 3 months, 1 week ago by js.

[Olaf Participant Topics: 4 Replies: 2249 Points: 5,494Rank: Community MVP]

js wrote:

++ after the variable increments after sending the value, ++ before the variable increments before sending the value.

… OK but I would expect the same behaviour on all systems and all versions. Wouldn’t you? 😉

[js Participant Topics: 29 Replies: 814 Points: 2,456Rank: Community Hero]

I don’t know what you mean. It works the way I said, in ps 5 and 7, with or without parentheses.

[Olaf Participant Topics: 4 Replies: 2249 Points: 5,494Rank: Community MVP]

OK, but obviously it does not work as expected for all systems. Kiran confirmed it and it does not work on my system.

[js Participant Topics: 29 Replies: 814 Points: 2,456Rank: Community Hero]

Kirin is mistaken.

[Olaf Participant Topics: 4 Replies: 2249 Points: 5,494Rank: Community MVP]

Possible. 😉 @Kiran Did you reset your console on the system before you tried to confirm it?

[Kiran Moderator Topics: 3 Replies: 222 Points: 1,206Rank: Community Hero]

js wrote:

++ after the variable increments after sending the value, ++ before the variable increments before sending the value.

This is completely make sense.

[Kiran]

js wrote:

Kirin is mistaken.

LOL. It is so weird!! Still working on my personal computer but not else where, very strange behavior.

• This reply was modified 3 months, 1 week ago by Kiran.

[Shane]

For what it is worth, I was going through basic code shown in the book, “Windows’ PowerShell Programming for the absolute beginner” third edition, when I found this abnormality,  They were using powershell 4 in the book.

• This reply was modified 3 months, 1 week ago by Shane.
• This reply was modified 3 months, 1 week ago by Shane.

[js Participant Topics: 29 Replies: 814 Points: 2,456Rank: Community Hero]

Maybe you have something weird in your $profile?

[TonyD05 Participant Topics: 6 Replies: 93 Points: 428Rank: Contributor]

Here is what I get. JS is correct.

PS C:\> $x = 5
PS C:\> $x
5
PS C:\> $y = ($x++)
PS C:\> $y
5
PS C:\> $y = ($x++)
PS C:\> $y
6
PS C:\> $y = ($x++)
PS C:\> $y
7
PS C:\>

[Author]

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