powershell assigning output of a ps1 script to a variable - variables

Question

Let me start with I am very new to powershell and programming for that matter. I have a powershell script that takes some arguments and that outputs a value.
The result of the script is going to be something like 9/10 where 9 would be the number active out of the total amount of nodes. I want to assign the output to a variable so I can then call another script based on the value.
This is what I have tried, but it does not work:
$active = (./MyScript.ps1 lb uid **** site)
I have also tried the following which seems to assign the variable an empty string
$active = (./MyScript.ps1 lb uid **** site | out-string)
In both cases they run and give me the value immediately instead of assigning it to the variable. When I call the variable, I get no data.

Answer 1

I would embrace PowerShell's object-oriented nature and rather than output a string like "9/10", create an object with properties like NumActiveNodes and TotalNodes e.g. in your script output like so:
new-object psobject -Property #{NumActiveNodes = 9; TotalNodes = 10}
Of course, substitute in the dynamic values for num active and total nodes. Note that uncaptured objects will automatically appear on your script's output. Then, if this is your scripts only output, you can do this:
$obj = .\MyScript.ps1
$obj.NumActiveNodes
9
$obj.TotalNodes
10
It will make it nicer for those consuming the output of your script. In fact the output is somewhat self-documenting e.g.:
C:\PS> .\MyScript.ps1
NumActiveNodes TotalNodes
-------------- ----------
9 10
P.S. When did StackOverflow start sucking so badly at formatting PowerShell script?

Answer 2

If you don't want to change the script ( and assuming only that $avail_count/$total_count line is written by the script), you can do:
$var= powershell .\MyScript.ps1
Or just drop the write-host and have just $avail_count/$total_count
and then do:
$var = .\MyScript.ps1

Answer 3

you could just do a $global:foobar in your script and it will persist after the script is closed

Answer 4

I know, the question is a bit older, but it might help someone to find the right answer.
I had the similar problem with executing PS script with another PS script and saving the output into variable, here are 2 VERY good answers:
Mathias
mklement0
Hope it helps!
Please up-vote them if so, because they are really good!