Powershell array scope; why is my array empty?

Powershell array scope; why is my array empty?

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I want to have an array and add elements to it from different functions in my script. My example below illustrates where I might be misunderstanding something regarding scope. My understanding currently is that if an array is defined outside the function, and then elements are added inside the function, those elements should be available outside the function.

Function ListRunningServices
{
    $services+= Get-Service | ?{$_.Status -eq "Running"} | sort Name | select Name;
}

$services = @();
ListRunningServices;
$services;

What am I missing here? Perhaps my style is completely wrong.


The $services within the function block is scoped to the function. You can do something like the following instead:

Function ListRunningServices {
    Get-Service | ?{$_.Status -eq "Running"} | sort Name | select Name
}

$services = ListRunningServices
$services

Else, you may explicitly use global: to alter the scope:

Function ListRunningServices {
    $global:services = Get-Service | ?{$_.Status -eq "Running"} | sort Name | select Name
}

$services = @()
ListRunningServices
$services

Powershell array scope; why is my array empty?, I want to have an array and add elements to it from different functions in my script. My example below illustrates where I might be misunderstanding something  You can solve this with global variables, but using globals is genereally considered bad practice. If you use a generic collection type, like arraylist, instead of an array then you have an add() method that will update the collection in a parent scope without needing to explicitly scope it in the function:


You can solve this with global variables, but using globals is genereally considered bad practice. If you use a generic collection type, like arraylist, instead of an array then you have an add() method that will update the collection in a parent scope without needing to explicitly scope it in the function:

Function ListRunningServices
{
    Get-Service | ?{$_.Status -eq "Running"} | sort Name | select Name |
     ForEach-Object {$services.add($_)}
}

$services = New-Object collections.arraylist
ListRunningServices
$services

Topic: Array appears to be empty after passing to a , I want to have an array and add elements to it from different functions in my script. My example below illustrates where I might be misunderstanding something  The variable scope in PowerShell can be either local or global. By default, a variable has a local scope. A variable is bounded by its current scope; for example, a local variable can be available in a current function or script, while a global variable is active throughout the current PowerShell session.


$service in the scope of the function has nothing to do with the one outside the function.

Try :

Function ListRunningServices
{
    $services = @()
    $services+= Get-Service | ?{$_.Status -eq "Running"} | sort Name | select Name;
    return $services
}


$services = ListRunningServices
$services

Keeping most of your code you can use :

Function ListRunningServices
{
    $global:services+= Get-Service | ?{$_.Status -eq "Running"} | sort Name | select Name;
}

$services = @();
ListRunningServices;
$services;

You can read the full explanation in About_scope.

Clear-Variable, Is the array wrapped as an object? are the elements wrapped as an object? Is this a scope issue? Please help ASAP. Thanks. June 3, 2015 at 2:  PowerShell scopes protect access to variables, aliases, functions, and PowerShell drives by limiting where they can be read and changed. The basic rules of scope: An item you include in a scope is visible in the scope in which it was created and in any child scope, unless you explicitly make it private.


Powershell requires specifying the scope with prefixes on array variables. Seems that "normal String" variables don't. Use them like this:

# Visible everywhere inside the script file (f.ex: myNameScript.ps1)
$script:names = @()

Function AddStringToArray ([string]$i_name) {
    $script:names += $i_name
}

AddStringToArray -i_name "Markie"
AddStringToArray -i_name "Harry"

I know this is late, but I hope this helps at least someone.

about_scopes, As a result, the value of the variable is NULL (empty). If the variable PowerShell. Copy Example 2: Clear a variable in a child scope but not the parent scope. PowerShell supports the following scopes: Global: The scope that is in effect when PowerShell starts. Variables and functions that are present when PowerShell starts have been created in the global scope, such as automatic variables and preference variables.


PowerShell Variables and Arrays, Explains the concept of scope in PowerShell and shows how to set To specify the scope of a new variable, alias, or function, use a scope modifier. The $ptest variable is not visible in the script scope, the output is empty. In PowerShell, a “scope” refers to the current environment in which a script or command shell is operating. Scopes are used to protect certain objects within the environment from being unintentionally modified by scripts or functions.


[SOLVED] Powershell, Object [] in the table. To this variable you can write the output of any cmdlet. Variable Scope. The variable scope in PowerShell can be either local  An array is a data structure that is designed to store a collection of items. The items can be the same type or different types. Beginning in Windows PowerShell 3.0, a collection of zero or one object has some properties of arrays.


[SOLVED] Alternative to Clear-Variable, Second function doesn't return anything in array from the first function. PowerShell world, only able to see variables from the parent scope. Powershell - Pass array from one function to another becomes it's own little PowerShell world, only able to see variables from the parent scope. part of the