Logical operators (-and, -or, -not) in PowerShell - Practice Problems & Coding Challenges

Challenge - 5 Problems

💻 Command Output

intermediate

What is the output of this PowerShell command?

Consider the following command:

Write-Output ($true -and $false) -or $true

What will this output?

PowerShell

Write-Output ($true -and $false) -or $true

A FalseTrue

B False

C TrueFalse

D True

💡 Hint

Remember that -and has higher precedence than -or in PowerShell.

The expression evaluates ($true -and $false) first, which is False. Then False -or $true is True, so the output is True.

💻 Command Output

intermediate

What does this PowerShell expression output?

Evaluate this expression:

Write-Output -not ($false -or $false)

What is the output?

PowerShell

Write-Output -not ($false -or $false)

A False

B True

C FalseTrue

D TrueFalse

💡 Hint

Check what ($false -or $false) evaluates to before applying -not.

($false -or $false) is False, so -not False is True. The output is True.

📝 Syntax

advanced

Which option causes a syntax error in PowerShell?

Identify the option that will cause a syntax error when run in PowerShell:

A Write-Output ($true -and not $false)

B Write-Output ($true -or -not $false)

C Write-Output (-not ($true -or $false))

D Write-Output ($true -and -not $false)

💡 Hint

Check the correct usage of the -not operator in PowerShell.

Option A uses 'not' without the dash, which is invalid syntax in PowerShell. The correct operator is '-not'.

🔧 Debug

advanced

Why does this PowerShell script output 'True' instead of 'False'?

Given this script:

$a = $true
$b = $false
if ($a -or $b -and $false) { Write-Output 'True' } else { Write-Output 'False' }

Why does it output 'True' instead of 'False'?

PowerShell

$a = $true
$b = $false
if ($a -or $b -and $false) { Write-Output 'True' } else { Write-Output 'False' }

A Because -and has higher precedence than -or, so $b -and $false is evaluated first, resulting in False, then $a -or False is True, so output should be True.

B Because the entire condition is evaluated as ($a -or $b) -and $false, which is False.

C Because the script has a syntax error and defaults to output 'False'.

D Because -or has higher precedence than -and, so $a -or $b is True, then True -and $false is False, so output is False.

💡 Hint

Check operator precedence carefully in PowerShell.

In PowerShell, -and has higher precedence than -or, so $b -and $false is evaluated first (False), then $a -or False is True, so it outputs 'True'. A common mistake is evaluating left-to-right ignoring precedence: ($a -or $b) -and $false = True -and False = False.

🚀 Application

expert

Which script correctly filters files modified in the last 7 days and larger than 1MB?

You want to list files in 'C:\Logs' that were modified in the last 7 days AND are larger than 1MB. Which script correctly uses logical operators to do this?

A Get-ChildItem C:\Logs | Where-Object { -not ($_.LastWriteTime -lt (Get-Date).AddDays(-7)) -and $_.Length -gt 1MB }

B Get-ChildItem C:\Logs | Where-Object { $_.LastWriteTime -ge (Get-Date).AddDays(-7) -and-or $_.Length -gt 1MB }

C Get-ChildItem C:\Logs | Where-Object { $_.LastWriteTime -ge (Get-Date).AddDays(-7) -and $_.Length -gt 1MB }

D Get-ChildItem C:\Logs | Where-Object { $_.LastWriteTime -ge (Get-Date).AddDays(-7) -or $_.Length -gt 1MB }

💡 Hint

Check the logical operators and syntax carefully.

Option C correctly uses -ge to check files modified on or after 7 days ago (i.e., last 7 days) AND -and for size > 1MB (1MB is valid: 1048576 bytes). Option C uses equivalent logic with -not (... -lt ...) but is more complex. Option C uses -or (wrong logic). Option C uses invalid '-and-or'.