Regular Expressions 101

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An explanation of your regex will be automatically generated as you type.
Detailed match information will be displayed here automatically.
  • All Tokens
  • Common Tokens
  • General Tokens
  • Anchors
  • Meta Sequences
  • Quantifiers
  • Group Constructs
  • Character Classes
  • Flags/Modifiers
  • Substitution
  • A single character of: a, b or c
    [abc]
  • A single character of: a, b, c or d
    [[ab][cd]]
  • A character except: a, b or c
    [^abc]
  • A character in the range: a-z
    [a-z]
  • A character not in the range: a-z
    [^a-z]
  • A character in the range: a-z or A-Z
    [a-zA-Z]
  • Character class intersection
    [\w&&[^\d]]
  • Any single character
    .
  • Alternate - match either a or b
    a|b
  • Any whitespace character
    \s
  • Any non-whitespace character
    \S
  • Any digit
    \d
  • Any non-digit
    \D
  • Any word character
    \w
  • Any non-word character
    \W
  • Non-capturing group
    (?:...)
  • Capturing group
    (...)
  • Zero or one of a
    a?
  • Zero or more of a
    a*
  • One or more of a
    a+
  • Exactly 3 of a
    a{3}
  • 3 or more of a
    a{3,}
  • Between 3 and 6 of a
    a{3,6}
  • Start of string
    ^
  • End of string
    $
  • A word boundary
    \b
  • Non-word boundary
    \B

Regular Expression
No Match

"
"
gm

Test String

Substitution

Processing...

Code Generator

Generated Code

import java.util.regex.Matcher; import java.util.regex.Pattern; public class Example { public static void main(String[] args) { final String regex = "^(?:\\[[A-Z]*-\\d* \\/fixed\\] )?(?<type>\\w*)(?:\\((?<scope>[\\w$.\\-*\\/ ]*)\\))?: (?<subject>(?:.(?!(?i)\\/fixed))*)$"; final String string = "# without scope\n" + "feat: add REST endpoint /my-app/api/versions\n" + "fix: change git commit username\n" + "style: set indentation to 4 spaces\n" + "docs: explain new configuration preset\n\n" + "# with scope\n" + "feat(backend): add REST endpoint /my-app/api/versions\n" + "fix(default): change git commit username\n" + "style(npm): set indentation to 4 spaces\n" + "docs(terraform): explain new configuration preset\n\n" + "# smartcommit without scope\n" + "[CORE-1234 /fixed] feat: add REST endpoint /my-app/api/versions\n" + "[HDEFECT-1234 /fixed] fix: change git commit username\n" + "[HDEFECT-1234 /fixed] style: set indentation to 4 spaces\n" + "[HDEFECT-1234 /fixed] docs: explain new configuration preset\n\n" + "# smartcommit with scope\n" + "[CORE-1234 /fixed] feat(backend): add REST endpoint /my-app/api/versions\n" + "[HDEFECT-1234 /fixed] fix(default): change git commit username\n" + "[HDEFECT-1234 /fixed] style(npm): set indentation to 4 spaces\n" + "[HDEFECT-1234 /fixed] docs(terraform): explain new configuration preset\n\n" + "# not match - wrong smart commit\n" + "[core-1234 /fixed] feat(backend): add REST endpoint /my-app/api/versions\n" + "[hdefect-1234 /fixed] fix(default): change git commit username\n" + "[hdefect-1234 /fixed] style(npm): set indentation to 4 spaces\n" + "[hdefect-1234 /fixed] docs(terraform): explain new configuration preset\n\n" + "# not matched - use /fixed in title \n" + "[CORE-1234 /fixed] feat(backend): add REST endpoint /my-app/api/versions /fixed\n" + "[HDEFECT-1234 /fixed] fix(default): change git commit /fixed username\n" + "[HDEFECT-1234 /fixed] style(npm): set /FIXED indentation to 4 spaces\n" + "[HDEFECT-1234 /fixed] docs(terraform): /fixed explain new configuration preset\n"; final String subst = "$type $scope $subject"; final Pattern pattern = Pattern.compile(regex, Pattern.MULTILINE); final Matcher matcher = pattern.matcher(string); // The substituted value will be contained in the result variable final String result = matcher.replaceAll(subst); System.out.println("Substitution result: " + result); } }

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 Java, please visit: https://docs.oracle.com/javase/7/docs/api/java/util/regex/Pattern.html