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

/
/
gm

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 = "^:(?![^:]*([^:])[^:]*\\1)[dgimsuy]{0,7}:$"; final String string = "::\n" + ":g:\n" + ":d:\n" + ":i:\n" + ":m:\n" + ":s:\n" + ":u:\n" + ":y:\n" + ":dg:\n" + ":gi:\n" + ":ms:\n" + ":uy:\n" + ":sd:\n" + ":mu:\n" + ":yi:\n" + ":dgi:\n" + ":gms:\n" + ":iuy:\n" + ":sdm:\n" + ":ymu:\n" + ":dgim:\n" + ":gims:\n" + ":iysu:\n" + ":msuy:\n" + ":dgims:\n" + ":gimsu:\n" + ":iysum:\n" + ":mugsy:\n" + ":dsygiu:\n" + ":gsiumd:\n" + ":ydsugi:\n" + ":isgumy:\n" + ":mugydi:\n" + ":ysgmdi:\n" + ":sgydmi:\n" + ":yigdsm:\n" + ":mudysg:\n" + ":gsdiuy:\n" + ":digmsuy:\n" + ":sudgimy:\n" + ":ydugsim:\n" + ":mudyisg:\n" + ":sgimydu:\n" + ":ysgidum:\n" + ":muidsyg:\n" + ":gusdymi:\n" + ":yidgums:\n" + ":sugmidy:\n\n" + ":gg:\n" + ":dd:\n" + ":ii:\n" + ":mm:\n" + ":ss:\n" + ":uu:\n" + ":yy:\n" + ":dgg:\n" + ":idd:\n" + ":iig:\n" + ":mmm:\n" + ":sms:\n" + ":uuu:\n" + ":yyy:\n" + ":dggi:\n" + ":iddd:\n" + ":iigm:\n" + ":mmmm:\n" + ":smss:\n" + ":uuuu:\n" + ":yyyy:\n" + ":dggiu:\n" + ":idddm:\n" + ":iigmy:\n" + ":mmmms:\n" + ":smsss:\n" + ":uuuuy:\n" + ":yyyym:\n" + ":dgimsguy:\n" + ":ydsgimuy:\n" + ":dgimsuyy:"; 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