Regular Expressions 101

Save & Share

Flavor

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

Function

  • Match
  • Substitution
  • List
  • Unit Tests
/
(\[.*\])(=>?)\s+(\w+[\(\)\d+\.]+)\s+?(\".*\"|\{[\s\w]+\})?
/
g
1st Capturing Group
(\[.*\])
\[ matches the character [ with index 9110 (5B16 or 1338) literally (case sensitive)
.
matches any character (except for line terminators)
* matches the previous token between zero and unlimited times, as many times as possible, giving back as needed (greedy)
\] matches the character ] with index 9310 (5D16 or 1358) literally (case sensitive)
2nd Capturing Group
(=>?)
= matches the character = with index 6110 (3D16 or 758) literally (case sensitive)
>
matches the character > with index 6210 (3E16 or 768) literally (case sensitive)
\s
matches any whitespace character (equivalent to [\r\n\t\f\v \u00a0\u1680\u2000-\u200a\u2028\u2029\u202f\u205f\u3000\ufeff])
+ matches the previous token between one and unlimited times, as many times as possible, giving back as needed (greedy)
3rd Capturing Group
(\w+[\(\)\d+\.]+)
\w
matches any word character (equivalent to [a-zA-Z0-9_])
+ matches the previous token between one and unlimited times, as many times as possible, giving back as needed (greedy)
Match a single character present in the list below
[\(\)\d+\.]
+ matches the previous token between one and unlimited times, as many times as possible, giving back as needed (greedy)
\( matches the character ( with index 4010 (2816 or 508) literally (case sensitive)
\) matches the character ) with index 4110 (2916 or 518) literally (case sensitive)
\d matches a digit (equivalent to [0-9])
+ matches the character + with index 4310 (2B16 or 538) literally (case sensitive)
\. matches the character . with index 4610 (2E16 or 568) literally (case sensitive)
\s
matches any whitespace character (equivalent to [\r\n\t\f\v \u00a0\u1680\u2000-\u200a\u2028\u2029\u202f\u205f\u3000\ufeff])
+? matches the previous token between one and unlimited times, as few times as possible, expanding as needed (lazy)
4th Capturing Group
(\".*\"|\{[\s\w]+\})?
? matches the previous token between zero and one times, as many times as possible, giving back as needed (greedy)
1st Alternative
\".*\"
\" matches the character " with index 3410 (2216 or 428) literally (case sensitive)
.
matches any character (except for line terminators)
* matches the previous token between zero and unlimited times, as many times as possible, giving back as needed (greedy)
\" matches the character " with index 3410 (2216 or 428) literally (case sensitive)
2nd Alternative
\{[\s\w]+\}
\{ matches the character { with index 12310 (7B16 or 1738) literally (case sensitive)
Match a single character present in the list below
[\s\w]
+ matches the previous token between one and unlimited times, as many times as possible, giving back as needed (greedy)
\s matches any whitespace character (equivalent to [\r\n\t\f\v \u00a0\u1680\u2000-\u200a\u2028\u2029\u202f\u205f\u3000\ufeff])
\w matches any word character (equivalent to [a-zA-Z0-9_])
\} matches the character } with index 12510 (7D16 or 1758) literally (case sensitive)
Global pattern flags
g modifier: global. All matches (don't return after first match)
Your regular expression does not match the subject string.

Regular Expression
No Match

/
/
g

Test String

Substitution

Processing...

Code Generator

Generated Code

Loading code sample...
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report.
For a full regex reference for JavaScript, please visit: https://developer.mozilla.org/en/docs/Web/JavaScript/Guide/Regular_Expressions