This article discusses two ways of saving PowerShell output into a variable. In each method, we will work on examples to cement the ideas.

Method 1: Using the Assignment Operator (=)

The most common way to save the output of a PowerShell command into a variable is using:

$var = <command>

Now, you can use the $var variable to perform further operations on the output of the <command>.

# Save an array of 5 elements into a variable 
$var1 = 1, 2, 4, -5, 9
# Display the array by calling the variable
$var1
# Count the number of elements in the array
$var1.Count # Output: 5

Note: when the <command> runs successfully without an error, the output is sent to the success stream (stream #1), and if the <command> execution ends in error, the result is streamed to the error stream (stream #2).

In the $var = <command> line, the $var variable only picks data from the success stream (not error steam). In the example below, Get-ChildItem attempts to get child items from a folder that doesn’t exist, leading to an error. Notice that the variable $var2 does not pick the error; instead, the error output is sent to the console.

$var2 = Get-ChildItem "./test_folder"
$var 2

If you want also to pick the error output on the variable, use the following line to redirect the output.

$var = <command> 2>&1

The 2>&1 means we want to redirect the content of the error stream (Stream #2) to the success stream (Stream #1), which can now be stored on the variable.

The example above shows that the error message has now been captured in the variable $var2.

Note: the redirection command given above only works from within PowerShell. If you run an external command, you may need to modify the command slightly – enclose 2>&1 in quotes, that is

$var = <command> "2>&1"

For example, the following command runs the dir using cmd.exe (not PowerShell).

$var2 = cmd /c dir "Desktop1" "2>&1"
$var2

The assignment operator can also be used with chained commands, as shown below. In this case, the output of <command-3> is saved on the $var

$var = <command-1> | <command-2> | <command-3>

Example:

$var2 = 3, 4, 5, 6, -6 | Sort-Object | Select-Object -First 1
$var2

Method 2: Using the -OutVariable or -Ov Parameter

Note that in Method 1, when a variable captures command output, the output is not printed to the console unless you run the variable name as a command.

This is where this method comes in. The -OutVariable parameter allows us to save the data in a variable while letting it get printed on the console.

You can capture the output to a variable using the following syntax:

<command> -OutVariable var_name
$var_name

For chained commands, you will use this

<command-1> | <command-2> -OutVariable var_name
$var_name

For example,

Write-Output "Hello World" |Select-Object Length -OutVariable var5
$var5

The code above takes the “Hello World” string, gets its length, and saves the output on the $var5 variable.

Conclusion

This guide discussed two methods for saving PowerShell output into a variable. The first method uses the assignment operator (=), and the second method uses the -OutVariable parameter. In most cases, Method 1 does the job. The second method is handy if you want to save your data in a variable while still letting it get printed on the console.