Environment variables in PowerShell - Practice Problems & Coding Challenges

Challenge - 5 Problems

💻 Command Output

intermediate

What is the output of this PowerShell command?

Consider the following command executed in PowerShell. What will it output?

PowerShell

Write-Output $env:USERNAME

A The literal string '$env:USERNAME'

B An empty string

C The current user's username as a string, e.g., 'Alice'

D A runtime error indicating variable not found

💡 Hint

Environment variables in PowerShell are accessed with $env: prefix.

The $env:USERNAME variable contains the current user's username. Write-Output prints its value.

📝 Syntax

intermediate

Which command correctly sets a new environment variable in PowerShell for the current session?

You want to set an environment variable named 'MY_VAR' with value 'HelloWorld' for the current PowerShell session. Which command is correct?

A set-env MY_VAR 'HelloWorld'

B $env:MY_VAR = 'HelloWorld'

C export MY_VAR='HelloWorld'

D env MY_VAR = 'HelloWorld'

💡 Hint

PowerShell uses $env: prefix to set environment variables.

In PowerShell, environment variables are set by assigning a value to $env:VariableName.

🔧 Debug

advanced

Why does this script fail to update the environment variable permanently?

This script tries to set an environment variable permanently but it doesn't work as expected. Why? $env:PATH = "$env:PATH;C:\NewFolder"

PowerShell

$env:PATH = "$env:PATH;C:\NewFolder"

A Because the syntax for appending to PATH is incorrect and causes a syntax error

B Because the path separator should be a colon ':' instead of a semicolon ';'

C Because environment variables cannot be changed in PowerShell

D Because $env:PATH only changes the variable for the current session, not permanently

💡 Hint

Think about session scope vs permanent environment variables.

Assigning to $env:PATH changes the variable only for the current PowerShell session. To change it permanently, you must modify the registry or use system settings.

🚀 Application

advanced

How to retrieve and display all environment variables in PowerShell?

You want to list all environment variables and their values in PowerShell. Which command will do this?

A Get-ChildItem Env:

B Get-EnvVariables

C ls $env:

D dir $env:USERNAME

💡 Hint

Environment variables are stored in a special drive in PowerShell.

Get-ChildItem Env: lists all environment variables and their values because Env: is a PS drive for environment variables.

🧠 Conceptual

expert

What happens when you run this PowerShell command?

What is the output or effect of running this command? [Environment]::SetEnvironmentVariable('TEST_VAR', '123', 'User') Write-Output $env:TEST_VAR

PowerShell

[Environment]::SetEnvironmentVariable('TEST_VAR', '123', 'User')
Write-Output $env:TEST_VAR

A Outputs nothing because the variable is set permanently but not updated in the current session

B Outputs the previous value of TEST_VAR before the change

C Throws a runtime error because SetEnvironmentVariable is not valid in PowerShell

D Outputs '123' because the variable is immediately available in the session

💡 Hint

Think about session environment variables vs permanent environment variables.

SetEnvironmentVariable with 'User' scope sets the variable permanently but does not update the current session's environment variables. So $env:TEST_VAR remains unchanged until a new session starts.