Switch with wildcard and regex in PowerShell - Practice Problems & Coding Challenges

Challenge - 5 Problems

💻 Command Output

intermediate

Output of Switch with Wildcard Matching

What is the output of this PowerShell script using switch with wildcard matching?

PowerShell

$input = "file123.txt"

switch -Wildcard ($input) {
  "file*" {"Matched file pattern"}
  "data*" {"Matched data pattern"}
  default {"No match"}
}

A No match

B Matched file pattern

C file123.txt

D Matched data pattern

💡 Hint

Remember that -Wildcard matches patterns with * as a wildcard.

The input 'file123.txt' matches the wildcard pattern 'file*', so the switch outputs 'Matched file pattern'.

💻 Command Output

intermediate

Switch with Regex Matching Output

What will this PowerShell switch statement output when using regex matching?

PowerShell

$input = "123-45-6789"

switch -Regex ($input) {
  '^\d{3}-\d{2}-\d{4}$' {"SSN format detected"}
  '^\w+@\w+\.com$' {"Email format detected"}
  default {"Unknown format"}
}

A Unknown format

B Email format detected

C SSN format detected

D 123-45-6789

💡 Hint

Look at the regex patterns and see which matches the input string.

The input matches the SSN regex pattern exactly, so the switch outputs 'SSN format detected'.

🔧 Debug

advanced

Identify the Error in Switch with Wildcard

This PowerShell script is intended to match inputs starting with 'test' using wildcard in switch, but it throws an error. What is the cause?

PowerShell

$input = "testing123"

switch ($input) {
  -Wildcard "test*" {"Starts with test"}
  default {"No match"}
}

A The switch statement requires -Regex parameter for wildcard matching

B The wildcard pattern must be in single quotes, not double quotes

C The input variable must be declared before the switch statement

D The -Wildcard parameter must be after the switch keyword, not inside the block

💡 Hint

Check where the -Wildcard parameter is placed in the switch syntax.

The -Wildcard parameter is a switch statement option and must be placed immediately after the switch keyword, not inside the block.

🚀 Application

advanced

Using Switch with Mixed Wildcard and Regex

You want to write a PowerShell switch statement that matches inputs starting with 'log' using wildcard and inputs matching a date format using regex. Which code snippet correctly implements this?

A

switch ($input) {
  {$_ -like "log*"} {"Log file"}
  {$_ -match '^\d{4}-\d{2}-\d{2}$'} {"Date format"}
  default {"No match"}
}

B

switch ($input) {
  -Wildcard "log*" {"Log file"}
  -Regex '^\d{4}-\d{2}-\d{2}$' {"Date format"}
  default {"No match"}
}

C

switch -Wildcard ($input) {
  "log*" {"Log file"}
  -Regex '^\d{4}-\d{2}-\d{2}$' {"Date format"}
  default {"No match"}
}

D

switch -Wildcard -Regex ($input) {
  "log*" {"Log file"}
  '^\d{4}-\d{2}-\d{2}$' {"Date format"}
  default {"No match"}
}

💡 Hint

PowerShell switch can only use one matching mode at a time; use script blocks for mixed matching.

PowerShell switch supports only one matching mode per statement. To mix wildcard and regex, use script blocks with conditions inside the switch.

🧠 Conceptual

expert

Behavior of Switch with Wildcard and Regex on Multiple Matches

In PowerShell, when using switch with the -Wildcard parameter, what happens if multiple patterns match the input? How does this differ from using -Regex with multiple matches?

A Both -Wildcard and -Regex run all matching cases

B With -Wildcard, all matching cases run; with -Regex, only the first matching case runs

C Both -Wildcard and -Regex run only the first matching case

D With -Wildcard, only the first matching case runs; with -Regex, all matching cases run

💡 Hint

Think about how switch processes multiple matches in PowerShell.

PowerShell switch runs all matching cases for both -Wildcard and -Regex modes, not just the first match.