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 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]
  • 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

Code Generator

Language

Generated Code

import java.util.regex.Matcher; import java.util.regex.Pattern; public class Example { public static void main(String[] args) { final String regex = "^.*?((?:\\s+\\d+\\.\\s+Nx?[a-h][1-8]\\s+[RBKQN]?x?[a-h][1-8]){2,}).*$"; final String string = "[Event \"Live Chess\"] [Site \"Chess.com\"] [Date \"2023.02.17\"] [Round \"-\"] [White \"-\"] [Black \"-\"] [Result \"1-0\"] [WhiteElo \"925\"] [BlackElo \"939\"] [TimeControl \"180+2\"] [EndTime \"17:39:13 PST\"] [Termination \"- won by checkmate\"]\n\n" + "e4 e5 2. Nc3 d6 3. Bc4 h6 4. d3 Nc6 5. f4 Qe7 6. Nf3 Be6 7. f5 Bxc4 8. dxc4 O-O-O 9. b3 Nf6 10. O-O g5 11. fxg6 fxg6 12. Nh4 g5 13. Ng6 Qg7 14. Nxh8 Qxh8 15. Nd5 Nxd5 16. exd5 Nd4 17. c3 Nxb3 18. axb3 a6 19. b4 Be7 20. Qg4+ Kb8 21. b5 axb5 22. cxb5 b6 23. Qa4 Kc8 24. Qa8+ Kd7 25. Qc6+ Kc8 26. Ra8# 1-0\n\n" + "[Event \"Live Chess\"] [Site \"Chess.com\"] [Date \"2023.02.17\"] [Round \"-\"] [White \"-\"] [Black \"-\"] [Result \"1-0\"] [WhiteElo \"914\"] [BlackElo \"841\"] [TimeControl \"180+2\"] [EndTime \"19:06:57 PST\"] [Termination \"- won by resignation\"]\n\n" + "e4 e5 2. Nc3 Nc6 3. Bc4 Nf6 4. d3 Bc5 5. Na4 Bb4+ 6. c3 Be7 7. f4 b5 8. Bxb5 a6 9. Bc4 O-O 10. f5 d5 11. exd5 Nxd5 12. Nf3 Bxf5 13. O-O Bc5+ 14. Nxc5 Nf4 15. Nxe5 Nxe5 16. Rxf4 Bg4 17. Rxg4 Nxg4 18. Qxg4 Re8 19. Bh6 g6 1-0"; final Pattern pattern = Pattern.compile(regex, Pattern.MULTILINE); final Matcher matcher = pattern.matcher(string); while (matcher.find()) { System.out.println("Full match: " + matcher.group(0)); for (int i = 1; i <= matcher.groupCount(); i++) { System.out.println("Group " + i + ": " + matcher.group(i)); } } } }

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