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"
"
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 = "(?:(?P<EngDate>[a-zA-Z]+\\s)??(?P<Date0>(?<!\\.)(?:\\d{1,2}(?=[,\\s.\\/-])|\\d{4}))\\.??(?(1),?)(?P<d_sep>[\\s\\.\\/-])?(?:(?P<Date1>[^\\W\\d_]+|\\d{1,2})(?(3)(?P=d_sep)))?(?(1)(?:\\s\\d{2}:\\d{2}:\\d{2}\\s\\w+\\s)?)(?P<Date2>\\d{2}|\\d{4})(?!\\:|\\.|\\d))|(?:(?<!\\d{2})(?P<Hours>[0-2]?\\d)[\\:\\.](?P<Minutes>[0-6]\\d)(?:[\\:\\.](?P<Seconds>[0-6]\\d))?(?:[,\\.](?P<SenodsFraction>\\d{3}|\\d{6}))?(?:\\so'clock)?(?:(?:[\\.,\\s,\\w+\\s]?(?:(?P<Z>(?:[a-zA-Z]{3,5})|(?:[+-]\\d\\d?:?[0,3,4]?[0,5]?))|(?P<s>PD|AM|PM|am|pm)))+)?)"; final String string = "04.march.2012 9:07:00\n" + "1999-03-22T05:06:07.000\n\n" + "20150420\n" + "14 мая 2015 08:30:43\n" + "1999 03 22T05:06:07.000+01:00\n" + " \n" + "22.3.19 5:06:07\n" + "5:06:07 22.3.19\n" + "22. March 1999\n\n\n" + "1999-03-22 5:06:07.PD \n\n" + "March 22, 1999\n" + "March 22 1999\n\n" + "22/3/1999 5:06 AM\n\n" + "Mar 22 05:06:07 CET 1999\n\n" + "Mon Mar 22 05:06:07 CET 1999\n\n\n\n" + " \n" + "Monday, March 22, 1999 5:06:07 o'clock AM CET\n\n" + "22-Mar-1999 5:06:07 AM CET\n\n" + "22-Mar-1999 5:06:07 CET AM\n\n" + "1999-03-22 5.06.07.PD CET\n\n" + "Monday, March 22, 1999 5:06:07 AM CET"; 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