Pipeline object flow in PowerShell - Practice Problems & Coding Challenges

Challenge - 5 Problems

💻 Command Output

intermediate

What is the output of this PowerShell pipeline?

Consider the following PowerShell command pipeline. What will be the output?

PowerShell

1..5 | Where-Object { $_ % 2 -eq 0 } | ForEach-Object { $_ * 3 }

A 2 4 6 8 10

B 3 6 9 12 15

C 6 12

D 3 9 15

💡 Hint

Think about which numbers pass the filter and what happens next.

The pipeline filters numbers 1 to 5 to only even numbers (2 and 4), then multiplies each by 3, resulting in 6 and 12.

🧠 Conceptual

intermediate

How does PowerShell pipeline pass data between commands?

In PowerShell, what is passed from one command to the next in a pipeline?

A Text strings representing command output

B Raw bytes of command output

C File paths of output files

D Objects representing data

💡 Hint

PowerShell pipelines are different from traditional text-based shells.

PowerShell pipelines pass objects, not just text, allowing rich data to flow between commands.

📝 Syntax

advanced

Which pipeline syntax correctly filters and selects properties?

Which of the following PowerShell pipelines correctly filters processes with CPU usage over 100 and selects their names?

A Get-Process | Where-Object { $_.CPU -gt 100 } | Select-Object Name

B Get-Process | Where-Object CPU -gt 100 | Select-Object Name

C Get-Process | Where-Object { CPU > 100 } | Select-Object Name

D Get-Process | Where-Object { $_.CPU > 100 } | Select Name

💡 Hint

Remember the syntax for script blocks and property access in Where-Object.

Option A uses the correct script block syntax with $_ to access the CPU property and Select-Object to pick the Name property.

🔧 Debug

advanced

Why does this pipeline produce no output?

Given the pipeline below, why does it produce no output? Get-Service | Where-Object { $_.Status -eq 'Running' } | Where-Object { $_.Name -like 'X*' }

PowerShell

Get-Service | Where-Object { $_.Status -eq 'Running' } | Where-Object { $_.Name -like 'X*' }

A No services have names starting with 'X' while running

B The -like operator is case-sensitive and fails

C The pipeline syntax is invalid and causes an error

D Get-Service does not output objects with Status property

💡 Hint

Check the actual service names and their statuses on your system.

The pipeline is correct but likely no running service has a name starting with 'X', so the filter returns no objects.

🚀 Application

expert

How many objects are passed through this pipeline?

How many objects does the pipeline output? 1..10 | ForEach-Object { if ($_ % 3 -eq 0) { $_ } }

PowerShell

1..10 | ForEach-Object { if ($_ % 3 -eq 0) { $_ } }

A 10

B 3

C 0

D 7

💡 Hint

Consider what happens when the if condition is false inside ForEach-Object.

For numbers 1 to 10, the if outputs the number only if divisible by 3 (3,6,9). When the condition is false, the scriptblock produces no output, so only 3 objects are output.