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

r"
"
gms

Test String

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 = "(^\\d+(?!\\.).*?)(?=^\\s*\\d)"; final String string = "7. On 6 March 2013, the Appeals Chamber filed the Decision on Victim \n" + "Participation, in which it decided that the victims “may, through their legal \n\n" + "1\n" + " The full citation, including the ICC registration reference of all designations and abbreviations used in \n" + "this judgment are included in Annex 1. \n" + "2\n" + " A more detailed procedural history is set out in Annex 2 of this judgment. \n" + "ICC-01/04-02/12-271-Corr 07-04-2015 7/117 EK A\n\n" + " 8/117 \n" + "representatives, participate in the present appeal proceedings for the purpose of \n" + "presenting their views and concerns in respect of their personal interests in the issues \n" + "on appeal”.3\n\n" + "8. On 19 March 2013, the Prosecutor filed, confidentially, ex parte, available to the \n" + "Prosecutor and Mr Ngudjolo only, the Document in Support of the Appeal. The \n" + "Prosecutor filed a confidential redacted version of the Document in Support of the \n" + "Appeal on 22 March 2013, and a public redacted version of the Document in Support \n" + "of the Appeal on 3 April 2013. In the redacted version of the Document in Support of \n" + "the Appeal, the Prosecutor’s entire third ground of appeal was redacted. \n"; final Pattern pattern = Pattern.compile(regex, Pattern.MULTILINE | Pattern.DOTALL); 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