Regular Expressions 101

@regex101DonateSponsorContactBug Reports & FeedbackWikiWhats new?

Save & Share

Save Regex
ctrl+s
Update Regex
ctrl+⇧+s

Flavor

PCRE2 (PHP >=7.3)
PCRE (PHP <7.3)
ECMAScript (JavaScript)
Python
Golang
Java 8

Function

Match
Substitution
List
Unit Tests

Tools

Code Generator

Sponsor

Jamstack at Scale

id \[([\d\w-]*)\]

matches the characters id literally (case sensitive)

\[ matches the character [ with index 91₁₀ (5B₁₆ or 133₈) literally (case sensitive)

1st Capturing Group

([\d\w-]*)

Match a single character present in the list below

[\d\w-]

* matches the previous token between zero and unlimited times, as many times as possible, giving back as needed (greedy)

\d matches a digit (equivalent to [0-9])

\w matches any word character (equivalent to [a-zA-Z0-9_])

- matches the character - with index 45₁₀ (2D₁₆ or 55₈) literally (case sensitive)

This hyphen is treated literally, which might be confusing for others. Consider escaping it or placing at the start or end of the class!

\] matches the character ] with index 93₁₀ (5D₁₆ or 135₈) literally (case sensitive)

Global pattern flags

g modifier: global. All matches (don't return after first match)

m modifier: multi line. Causes ^ and $ to match the begin/end of each line (not only begin/end of string)

Regular Expressions 101

Save & Share

Flavor

Function

Tools

Explanation

Match Information

Quick Reference

Regular Expression
No Match

Test String

Code Generator

Language

Generated Code

Regular Expressions 101

Save & Share

Flavor

Function

Tools

Explanation

Match Information

Quick Reference

Regular Expressionv1No Match

Test String

Code Generator

Language

Generated Code

Regular Expressions 101

Regular Expression
No Match