Pipeline concept (|) 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 it output?

PowerShell

1..5 | Where-Object { $_ % 2 -eq 0 } | ForEach-Object { $_ * 10 }

A 20`n40

B 2`n4`n6`n8`n10

C 10`n20

D 1`n3`n5

💡 Hint

Think about filtering even numbers first, then multiplying each by 10.

The pipeline first selects even numbers from 1 to 5 (2 and 4), then multiplies each by 10, resulting in 20 and 40.

💻 Command Output

intermediate

What does this pipeline output?

What is the output of this PowerShell command?

PowerShell

'apple','banana','cherry' | Where-Object { $_.Length -gt 5 } | Sort-Object

A cherry`nbanana

B banana`ncherry

C apple`nbanana`ncherry

D apple

💡 Hint

Filter words longer than 5 letters, then sort alphabetically.

Only 'banana' and 'cherry' have length greater than 5. Sorting alphabetically gives 'banana' then 'cherry'.

🔧 Debug

advanced

Why does this pipeline cause an error?

This PowerShell pipeline throws an error. What is the cause?

PowerShell

1..3 | ForEach-Object { $_ / 0 } | Where-Object { $_ -gt 1 }

A Division by zero error in ForEach-Object block

B Where-Object cannot process pipeline input

C Syntax error due to missing parentheses

D No error; outputs 1, 2, 3

💡 Hint

Check the operation inside ForEach-Object carefully.

Dividing any number by zero causes a runtime error in PowerShell, so the pipeline fails at ForEach-Object.

🚀 Application

advanced

Which pipeline command lists files larger than 1MB and sorts by size?

You want to list files in the current folder larger than 1MB, sorted from largest to smallest. Which pipeline command does this?

A Get-ChildItem | Sort-Object Length -Descending | Where-Object { $_.Length -gt 1MB }

B Get-ChildItem | Sort-Object Length | Where-Object { $_.Length -lt 1MB }

C Get-ChildItem | Where-Object { $_.Length -lt 1MB } | Sort-Object Length

D Get-ChildItem | Where-Object { $_.Length -gt 1MB } | Sort-Object Length -Descending

💡 Hint

Filter first, then sort descending by size.

Filtering first reduces items to those larger than 1MB, then sorting descending shows largest first. Option D sorts first then filters, which is less efficient but works; however, the question expects filtering first.

🧠 Conceptual

expert

What is the main benefit of using pipelines in PowerShell scripting?

Why do PowerShell users prefer pipelines (|) when writing scripts?

A They convert all output to plain text for easier reading

B They automatically parallelize commands to run on multiple CPU cores

C They allow chaining commands so output of one is input to next, enabling efficient data processing

D They prevent any errors from stopping the script execution

💡 Hint

Think about how data flows between commands.

Pipelines let you connect commands so the output of one command flows directly as input to the next, making scripts simpler and efficient.