Regular expressions with -match in PowerShell - Practice Problems & Coding Challenges

Challenge - 5 Problems

💻 Command Output

intermediate

What is the output of this PowerShell code using -match?

Consider this PowerShell snippet:

$text = 'Hello123'

if ($text -match '\d{3}$') { 'Match found' } else { 'No match' }

What will it output?

PowerShell

$text = 'Hello123'
if ($text -match '\d{3}$') { 'Match found' } else { 'No match' }

A Match found

B No match

C True

D False

💡 Hint

Check if the string ends with exactly three digits.

The regex '\d{3}$' looks for exactly three digits at the end of the string. 'Hello123' ends with '123', so it matches.

📝 Syntax

intermediate

Which option correctly uses -match to check for a word starting with 'a'?

Which PowerShell command correctly checks if the variable $word starts with the letter 'a'?

A $word -match '[a]'

B $word -match 'a$'

C $word -match '^a'

D $word -match 'a*'

💡 Hint

Use the caret ^ to match the start of a string.

Regex '^a' matches strings starting with 'a'. Option C matches strings ending with 'a'. Option C matches zero or more 'a's anywhere. Option C matches any string containing 'a'.

🔧 Debug

advanced

Why does this -match expression fail to find a match?

Given this code:

$input = 'User-01'

if ($input -match '\w+\d+') { 'Found' } else { 'Not found' }

It outputs 'Not found'. Why?

A Because -match is case sensitive and input has uppercase letters

B Because '\w+' matches letters and digits but the pattern expects digits immediately after letters without hyphen

C Because the backslashes are not escaped properly in the string

D Because the regex is missing anchors ^ and $

💡 Hint

Think about what '\w+' matches and the actual string structure.

The pattern '\w+\d+' expects one or more word characters followed immediately by one or more digits. 'User-01' has a hyphen between letters and digits, so the digits are not immediately after letters, causing no match.

🚀 Application

advanced

Which command extracts the first email from a string using -match?

You have this string:

$text = 'Contact us at [e-mail] or [e-mail].'

Which command extracts the first email address correctly?

A $text -match '[\w.-]+@[\w.-]+\.\w{2,}'; $matches[0]

B $text -match '[\w.-]+@[\w.-]+\.\w{2,}'; $matches[1]

C $text -match '\b[\w.-]+@[\w.-]+\.\w{2,}\b'; $matches[1]

D $text -match '\b[\w.-]+@[\w.-]+\.\w{2,}\b'; $matches[0]

💡 Hint

Remember the automatic variable $matches stores the matched text at index 0.

Option D uses word boundaries and captures the first email correctly. $matches[0] contains the matched string. Other options use wrong indices or miss word boundaries.

🧠 Conceptual

expert

What is the value of $matches after this -match operation?

Run this code:

$string = 'Order #12345 placed'

$string -match 'Order #(\d+)'

What is the value of $matches?

A @{0='Order #12345'; 1='12345'}

B @{0='12345'; 1='Order #12345'}

C @{0='Order #'; 1='12345'}

D @{0='Order #12345'; 1='#12345'}

💡 Hint

The first element is the full match, the next elements are capture groups.

$matches[0] holds the entire matched string 'Order #12345'. $matches[1] holds the first captured group '12345'.