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 = "User Name: (?<User_Name>[^ \\n]+)"; final String string = "LogName=Application\n" + "EventCode=1004\n" + "EventType=4\n" + "ComputerName=Test.local\n" + "User=NOT_TRANSLATED\n" + "Sid=S-1-5-21-2704069758-3089908202-2921546158-1104\n" + "SidType=0\n" + "SourceName=RoxioBurn\n" + "Type=Information\n" + "RecordNumber=16834\n" + "Keywords=Classic\n" + "TaskCategory=Optical Disc\n" + "OpCode=Info\n" + "Message=Date: Wed Feb 28 14:22:59 2024\n" + " Computer Name: COM-HV01\n" + " User Name: Test\\test.user\n" + " Writing is completed on drive (E:). Project includes 0 folder(s) and 1 file(s).\n" + " Volume Label: 2024-02-28 \n" + " Volume SN: 0\n" + " Volume ID: \\??\\Volume{b282bf1c-3dde-11ed-b48e-806e6f6e6963}\n" + " Type: Unknown\n" + " Status Of Media: Appendable,Blank,Closed session\n" + " Files: C:\\ProgramData\\Roxio Log Files\\Test.test.user_20240228142142.txt SHA1: 7c347a6724dcd243d396f9bb5e560142f26b8aa4\n" + " File System: None\n" + " Disc Number: 1\n" + " Encryption: Yes\n" + " User Password: Yes\n" + " Spanned Set: No\n" + " Data Size On Disc Set: 511 Bytes\n" + " Network Volume: No"; 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