DEV Community

Cover image for Top 50 Useful Regex Patterns
Sh Raj
Sh Raj

Posted on • Edited on • Originally published at codexdindia.blogspot.com

Top 50 Useful Regex Patterns

#javascript #webdev #beginners #programming

Mastering Regular Expressions in JavaScript: Top 50 Useful Regex Patterns

Know More :- https://codexdindia.blogspot.com/2024/02/top-50-useful-regex-patterns.html
Join Discord ๐Ÿš€ :- https://discord.gg/26DFm2rku9

Introduction:

Regular expressions (regex) are a powerful tool for pattern matching and text manipulation in JavaScript. Whether you're validating user input, extracting data from strings, or replacing text, regex can streamline your coding tasks. In this article, we'll explore 50 useful regex patterns that every JavaScript developer should know. These regex patterns cover a wide range of common scenarios, from validating email addresses to parsing URLs and beyond.

1. Validating Email Addresses:

const emailRegex = /^[\w-]+(\.[\w-]+)*@([\w-]+\.)+[a-zA-Z]{2,7}$/;
Enter fullscreen mode Exit fullscreen mode

2. Validating URLs:

const urlRegex = /^(https?:\/\/)?([\da-z.-]+)\.([a-z.]{2,6})([/\w .-]*)*\/?$/;
Enter fullscreen mode Exit fullscreen mode

3. Validating Dates in YYYY-MM-DD Format:

const dateRegex = /^\d{4}-\d{2}-\d{2}$/;
Enter fullscreen mode Exit fullscreen mode

4. Validating Phone Numbers (US Format):

const phoneRegex = /^\(?(\d{3})\)?[- ]?(\d{3})[- ]?(\d{4})$/;
Enter fullscreen mode Exit fullscreen mode

5. Validating Postal Codes (US Format):

const postalCodeRegex = /^\d{5}(?:-\d{4})?$/;
Enter fullscreen mode Exit fullscreen mode

6. Validating Credit Card Numbers (Luhn Algorithm):

const creditCardRegex = /^(?:4[0-9]{12}(?:[0-9]{3})?|5[1-5][0-9]{14}|6(?:011|5[0-9][0-9])[0-9]{12}|3[47][0-9]{13}|3(?:0[0-5]|[68][0-9])[0-9]{11}|(?:2131|1800|35\d{3})\d{11})$/;
Enter fullscreen mode Exit fullscreen mode

7. Validating Social Security Numbers (SSN):

const ssnRegex = /^\d{3}-\d{2}-\d{4}$/;
Enter fullscreen mode Exit fullscreen mode

8. Validating IP Addresses (IPv4):

const ipRegex = /^(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)$/;
Enter fullscreen mode Exit fullscreen mode

9. Validating Hexadecimal Color Codes:

const hexColorRegex = /^#?([a-fA-F0-9]{6}|[a-fA-F0-9]{3})$/;
Enter fullscreen mode Exit fullscreen mode

10. Extracting All URLs from a String:

const extractURLs = /https?:\/\/\S+/g;
Enter fullscreen mode Exit fullscreen mode

11. Extracting All Email Addresses from a String:

const extractEmails = /[\w.-]+@[a-zA-Z-]+\.[a-zA-Z]{2,3}/g;
Enter fullscreen mode Exit fullscreen mode

12. Matching HTML Tags:

const htmlTagsRegex = /<([a-z]+)([^<]+)*(?:>(.*)<\/\1>|\s+\/>)/gi;
Enter fullscreen mode Exit fullscreen mode

13. Matching HTML Comments:

const htmlCommentsRegex = /<!--[\s\S]*?-->/g;
Enter fullscreen mode Exit fullscreen mode

14. Matching CSS Classes:

const cssClassRegex = /\.([a-zA-Z_-][\w-]*)/g;
Enter fullscreen mode Exit fullscreen mode

15. Matching Twitter Handles:

const twitterHandleRegex = /@[a-zA-Z0-9_]+/g;
Enter fullscreen mode Exit fullscreen mode

16. Matching Hashtags:

const hashtagRegex = /#[a-zA-Z0-9_]+/g;
Enter fullscreen mode Exit fullscreen mode

17. Matching Mentions in Tweets:

const mentionRegex = /@([a-zA-Z0-9_]+)/g;
Enter fullscreen mode Exit fullscreen mode

18. Matching YouTube Video IDs in URLs:

const youtubeVideoIdRegex = /(?:https?:\/\/)?(?:www\.)?(?:youtube\.com\/(?:[^\/\n\s]+\/\S+\/|(?:v|e(?:mbed)?)\/|\S*?[?&]v=)|youtu\.be\/)([a-zA-Z0-9_-]{11})/;
Enter fullscreen mode Exit fullscreen mode

19. Matching Twitter URLs:

const twitterUrlRegex = /(?:https?:\/\/)?(?:www\.)?twitter\.com\/(#!\/)?[a-zA-Z0-9_]+/;
Enter fullscreen mode Exit fullscreen mode

20. Matching YouTube URLs:

const youtubeUrlRegex = /(?:https?:\/\/)?(?:www\.)?(?:youtube\.com\/(?:[^\/\n\s]+\/\S+\/|(?:v|e(?:mbed)?)\/|\S*?[?&]v=)|youtu\.be\/)([a-zA-Z0-9_-]{11})/;
Enter fullscreen mode Exit fullscreen mode

21. Matching Instagram Usernames:

const instagramUsernameRegex = /(?:https?:\/\/)?(?:www\.)?instagram\.com\/[a-zA-Z0-9_]+/;
Enter fullscreen mode Exit fullscreen mode

22. Matching Instagram URLs:

const instagramUrlRegex = /(?:https?:\/\/)?(?:www\.)?instagram\.com\/(p|tv|reel)\/[a-zA-Z0-9_]+/;
Enter fullscreen mode Exit fullscreen mode

23. Matching YouTube Playlist URLs:

const youtubePlaylistRegex = /(?:https?:\/\/)?(?:www\.)?youtube\.com\/playlist\?list=([a-zA-Z0-9_-]+)/;
Enter fullscreen mode Exit fullscreen mode

24. Matching Google Drive URLs:

const googleDriveUrlRegex = /(?:https?:\/\/)?drive\.google\.com\/(?:file\/d\/|open\?id=)([a-zA-Z0-9_-]+)/;
Enter fullscreen mode Exit fullscreen mode

25. Matching SoundCloud URLs:

const soundcloudUrlRegex = /(?:https?:\/\/)?(?:www\.)?soundcloud\.com\/[a-zA-Z0-9_-]+\/[a-zA-Z0-9_-]+/;
Enter fullscreen mode Exit fullscreen mode

26. Matching GitHub Repository URLs:

const githubRepoUrlRegex = /(?:https?:\/\/)?(?:www\.)?github\.com\/[a-zA-Z0-9_-]+\/[a-zA-Z0-9_-]+/;
Enter fullscreen mode Exit fullscreen mode

27. Matching GitHub Gist URLs:

const githubGistUrlRegex = /(?:https?:\/\/)?(?:www\.)?gist\.github\.com\/[a-zA-Z0-9_-]+\/[a-zA-Z0-9]+/;
Enter fullscreen mode Exit fullscreen mode

28. Matching Medium URLs:

const mediumUrlRegex = /(?:https?:\/\/)?(?:www\.)?medium\.com\/(@[a-zA-Z0-9_-]+)\/[a-zA-Z0-9_-]+/;
Enter fullscreen mode Exit fullscreen mode

29. Matching Stack Overflow URLs:

const stackoverflowUrlRegex = /(?:https?:\/\/)?(?:www\.)?stackoverflow\.com\/questions\/([0-9]+)/;
Enter fullscreen mode Exit fullscreen mode

30. Matching LinkedIn Profile URLs:

const linkedinProfileUrlRegex = /(?:https?:\/\/)?(?:www\.)?linkedin\.com\/in\/[a-zA-Z0-9_-]+/;
Enter fullscreen mode Exit fullscreen mode

31. Matching IPv6 Addresses:

const ipv6Regex = /(?:(?:(?:[0-9a-fA-F]{1,4}:){6}|(?=(?:[0-9a-fA-F]{0,4}:){2,6}(?:[0-9.]{1,3})){((?=.*(::))(?=(.*?::))(::)?(([0-9a-fA-F]{1,4}:){0,5}|:)((?::[0-9a-fA-F]{1,4}){1,2}:|(?:[0-9]{1,3}\.){3}[0-9]{1,3})))(%.+)?\b/;
Enter fullscreen mode Exit fullscreen mode

32. Matching Base64 Encoded Strings:

const base64Regex = /^[a-zA-Z0-9-_]+={0,2}$/;
Enter fullscreen mode Exit fullscreen mode

33. Matching Markdown Headings:

const markdownHeadingRegex = /^(#{1,6})\s(.+)/;
Enter fullscreen mode Exit fullscreen mode

34. Matching Markdown Links:

const markdownLinkRegex = /\[([^\]]+)\]\(([^)]+)\)/g;
Enter fullscreen mode Exit fullscreen mode

35. Matching HTML Entities:

const htmlEntityRegex = /&(?:[a-zA-Z]+|#\d+);/;
Enter fullscreen mode Exit fullscreen mode

36. Matching XML Tags:

const xmlTagRegex = /<([a-zA-Z]+)([^<]+)*(?:>(.*)<\/\1>|\s+\/>)/gi;
Enter fullscreen mode Exit fullscreen mode

37. Matching Docker Image Tags:

const dockerTagRegex = /^[a-zA-Z0-9][a-zA-Z0-9._-]{0,127}$/;
Enter fullscreen mode Exit fullscreen mode

38. Matching Semantic Versioning (SemVer):

const semverRegex = /^(0|[1-9]\d*)\.(0|[1-9]\d*)\.(0|[1-9]\d*)(?:-((?:0|[1-9]\d*|\d*[a-zA-Z-][0-9a-zA-Z-]*)?(?:\.(?:0|[1-9]\d*|\d*[a-zA-Z-][0-9a-zA-Z-]*))*))?(?:\+([0-9a-zA-Z-]+(?:\.[0-9a-zA-Z-]+)*))?$/;
Enter fullscreen mode Exit fullscreen mode

39. Matching YAML Front Matter:

const yamlFrontMatterRegex = /---\n([\s\S]*?)\n---/;
Enter fullscreen mode Exit fullscreen mode

40. Matching JSON Objects:

const jsonObjectRegex = /{[\s\S]*?}/;
Enter fullscreen mode Exit fullscreen mode

41. Matching JSON Arrays:

const jsonArrayRegex = /\[[\s\S]*?\]/;
Enter fullscreen mode Exit fullscreen mode

42. Matching CSS Color Codes:

const cssColorRegex = /#([0-9A-Fa-f]{6}|[0-9A-Fa-f]{3})/;
Enter fullscreen mode Exit fullscreen mode

43. Matching HTML Hexadecimal Entities:

const htmlHexEntityRegex = /&#x[0-9A-Fa-f]+;/;
Enter fullscreen mode Exit fullscreen mode

44. Matching HTML Decimal Entities:

const htmlDecimalEntityRegex = /&#\d+;/;
Enter fullscreen mode Exit fullscreen mode

45. Matching Base64 Data URLs:

const base64DataUrlRegex = /^data:([a-z]+)\/([a-z]+);base64,([^\s]+)/;
Enter fullscreen mode Exit fullscreen mode

46. Matching UUID (Universally Unique Identifier):

const uuidRegex = /^[0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[1-5][0-9a-fA-F]{3}-[89abAB][0-9a-fA-F]{3}-[0-9a-fA-F]{12}$/;
Enter fullscreen mode Exit fullscreen mode

47. Matching ISBN (International Standard Book Number):

const isbnRegex = /^(?:ISBN(?:-10)?:? ?)?(?=[0-9X]{10}$|(?=(?:[0-9]+[- ]){3})[- 0-9X]{13}$|97[89][0-9]{10}$|(?=(?:[0-9]+[- ]){4})[- 0-9]{17}$)(?:97[89][- ]?)?[0-9]{1,5}[- ]?(?:[0-9]+[- ]?){2}[0-9X]$/;
Enter fullscreen mode Exit fullscreen mode

48. Matching XML or HTML Comments:

const xmlHtmlCommentRegex = /<!--[\s\S]*?-->/;
Enter fullscreen mode Exit fullscreen mode

49. Matching Google Analytics Tracking IDs:

const googleAnalyticsIdRegex = /^(UA|YT|MO)-\d{4,}-\d{1,2}$/;
Enter fullscreen mode Exit fullscreen mode

50. Matching ISBN (International Standard Book Number) with Hyphens:

const isbnWithHyphensRegex = /^(?=(?:[0-9]+[- ]){3})[- 0-9]{13}$/;
Enter fullscreen mode Exit fullscreen mode

Conclusion:

Regular expressions are an indispensable tool for working with text in JavaScript. By mastering these 50 useful regex patterns, you can handle a wide range of tasks efficiently, from validating user input to extracting data from strings and more. Experiment with these regex patterns in your projects and adapt them as needed to suit your specific requirements. Happy coding!

Top comments (3)

Collapse
 
darkwiiplayer profile image
Info Comment hidden by post author - thread only accessible via permalink
๐’ŽWii ๐Ÿณ๏ธโ€โšง๏ธ •

Please don't use these, lots of them are wrong in very subtle ways that can cause massive headaches if they ever see production.

Collapse
 
sh20raj profile image
Sh Raj •

Rectify them and send me back I will update the Article ๐Ÿ‘

Collapse
 
xentzenith profile image
Ilker Ozturk •

You know finding REGEXes always painful thing. Appreciated!

Some comments have been hidden by the post's author - find out more

Read next

anhchienvu profile image

Working with GitHub OAuth Authentication

AnhChienVu -

kasir-barati profile image

Module declaration in TS

Mohammad Jawad (Kasir) Barati -

catundanatalia profile image

We are simplifying (literals(arrays and objects)) in Js.

Natรกlia Catunda -

leo_scott_357f10236fabe00 profile image

Preparing for Web3 in 2025: What Developers and Investors Need to Know

Leo Scott -