Matching Email Addresses:

• Example Text: "Please contact me at john.doe@example.com or jane@example.org"
• Regex: (?:[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,})
• Result: Matches john.doe@example.com and jane@example.org

Extracting URLs from Text:

• Example Text: "Visit our website at https://www.example.com or http://example.org"
• Regex: (?:http|https)://[^\s]+
• Result: Matches https://www.example.com and http://example.org

Parsing CSV Data:

• Example Text: "John,Doe,30\nJane,Smith,25\n"
• Regex: (\w+),(\w+),(\d+)
• Result: Matches John,Doe,30 and Jane,Smith,25. Captures "John", "Doe", and "30" in group 1, 2, and 3 respectively for the first match, and "Jane", "Smith", and "25" for the second match.

Extracting Hash Tags from Social Media Posts:

• Example Text: "Check out our new product #launch #excited"
• Regex: #\w+
• Result: Matches #launch and #excited

Extracting HTML Tags from Text:

• Example Text: "<p>This is a <b>bold</b> statement.</p>"
• Regex: <[^>]+>
• Result: Matches <p>, <b>, </b>, and </p>

Validating IPv4 Addresses:

• Example Text: "The server IP is 192.168.1.1"
• Regex: \b(?:\d{1,3}\.){3}\d{1,3}\b
• Result: Matches 192.168.1.1

Matching Markdown Links:

• Example Text: "Check out our website"
• Regex: \[(.*?)\]\((.*?)\)
• Result: Matches [our website](https://www.example.com). Captures "our website" and "https://www.example.com" in group 1 and 2 respectively.

Identifying Twitter Usernames:

• Example Text: "Follow me on Twitter @john_doe and @jane_smith"
• Regex: @([A-Za-z0-9_]+)
• Result: Matches @john_doe and @jane_smith. Captures "john_doe" and "jane_smith" in group 1.

Matching Scientific Notation:

• Example Text: "The speed of light is 3.00e8 m/s"
• Regex: \b\d+(\.\d+)?[eE][+-]?\d+\b
• Result: Matches 3.00e8

Extracting YouTube Video IDs from URLs:

• Example Text: "https://www.youtube.com/watch?v=dQw4w9WgXcQ"
• Regex: (?:youtu\.be/|youtube\.com(?:/embed/|/v/|/watch\?v=|/watch\?.+&v=))([^"&?/]+)
• Result: Matches dQw4w9WgXcQ

Extracting Dates from Text:

• Example Text: "The event is scheduled for 02/14/2024"
• Regex: \b\d{2}/\d{2}/\d{4}\b
• Result: Matches 02/14/2024

Identifying GitHub Repository Names:

• Example Text: "Check out my GitHub repository: https://github.com/user/repo"
• Regex: github\.com\/(\S+)\/(\S+)
• Result: Matches user and repo

Parsing Markdown Headings:

• Example Text: "# Introduction\n## Subheading\n### Sub-subheading"
• Regex: ^#{1,6}\s(.+)$
• Result: Matches Introduction, Subheading, and Sub-subheading

Extracting Currency Values:

• Example Text: "The price is $10.99"
• Regex: \$\d+(\.\d{2})?
• Result: Matches $10.99

Identifying Twitter Hashtags and Mentions:

• Example Text: "Great article! #DataScience is fascinating. @DataScientist"
• Regex: [@#][^\s#@]+
• Result: Matches #DataScience and @DataScientist

Matching HTML Attributes:

• Example Text: <a href="https://www.example.com">Click here</a>
• Regex: ([a-zA-Z-]+)="([^"]+)"
• Result: Matches href="https://www.example.com". Captures href and https://www.example.com in group 1 and 2 respectively.

Extracting File Extensions:

• Example Text: "The file is named document.pdf"
• Regex: \.([a-zA-Z0-9]+)$
• Result: Matches .pdf

Matching JavaScript Function Calls:

• Example Text: "Call myFunction(arg1, arg2)"
• Regex: \w+\(([^)]*)\)
• Result: Matches myFunction(arg1, arg2). Captures arg1, arg2 in group 1.

Identifying Roman Numerals:

• Example Text: "This is chapter IX of the book"
• Regex: \b[IVXLCDM]+\b
• Result: Matches IX

Extracting HTML Comments:

• Example Text: <!-- This is a comment -->
• Regex: <!--(.*?)-->
• Result: Matches <!-- This is a comment -->. Captures This is a comment in group 1.