Why regex enables pattern matching in PowerShell - See It in Action

Why regex enables pattern matching

📖 Scenario: You work in IT support and often need to find specific patterns in text logs to quickly spot errors or important messages.

🎯 Goal: Build a simple PowerShell script that uses regex to find all email addresses in a list of text lines.

📋 What You'll Learn

Create a list of text lines containing some email addresses

Create a regex pattern variable to match email addresses

Use a loop to find all matches in the list using the regex pattern

Print each found email address

💡 Why This Matters

🌍 Real World

IT support and system admins often scan logs or messages to find specific patterns like email addresses or error codes quickly.

💼 Career

Knowing regex and scripting helps automate searching and filtering tasks, saving time and reducing errors in daily work.

1

Create the list of text lines

Create a variable called lines and assign it an array with these exact strings: 'Contact us at [e-mail]', 'Send feedback to [e-mail]', 'No email here', 'Reach [e-mail] anytime'.

PowerShell

# Create the variable lines with the given strings
# Your code here

Need a hint?

Use @( ... ) to create an array in PowerShell.

2

Create the regex pattern variable

Create a variable called emailPattern and assign it the regex string '\b[\w.-]+@[\w.-]+\.\w{2,}\b' to match email addresses.

PowerShell

$lines = @(
    'Contact us at [e-mail]',
    'Send feedback to [e-mail]',
    'No email here',
    'Reach [e-mail] anytime'
)
# Create the variable emailPattern with the regex string
# Your code here

Need a hint?

Use double backslashes \\ in the string to escape backslashes in PowerShell.

3

Find all email addresses using regex

Use a foreach loop with variable line to go through $lines. Inside the loop, use [regex]::Matches($line, $emailPattern) to find matches. For each match, add the matched value to a list called foundEmails. Initialize foundEmails as an empty list before the loop.

PowerShell

$lines = @(
    'Contact us at [e-mail]',
    'Send feedback to [e-mail]',
    'No email here',
    'Reach [e-mail] anytime'
)
$emailPattern = '\b[\w.-]+@[\w.-]+\.\w{2,}\b'

# Initialize foundEmails as an empty list
# Use foreach loop to find matches and add them to foundEmails
# Your code here

Need a hint?

Use @() to create an empty array. Use nested loops to collect matches.

4

Print all found email addresses

Use foreach with variable email to go through $foundEmails and print each email using Write-Output.

PowerShell

$lines = @(
    'Contact us at [e-mail]',
    'Send feedback to [e-mail]',
    'No email here',
    'Reach [e-mail] anytime'
)
$emailPattern = '\b[\w.-]+@[\w.-]+\.\w{2,}\b'

$foundEmails = @()
foreach ($line in $lines) {
    $matches = [regex]::Matches($line, $emailPattern)
    foreach ($match in $matches) {
        $foundEmails += $match.Value
    }
}

# Print each email in foundEmails
# Your code here

Need a hint?

Use Write-Output inside a loop to print each email.