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"
"
mg

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 = "^(.*\\[(error|warning|notice|info|debug)\\].*)$"; final String string = "lu2-pre-sm-swap-manager1 (192.168.236.230) 2014-07-24 14:09:27,193 [debug] PRE-BCP 213.146.188.31 [marti.us] bcp:4934846 GET 3a90f85c /members/overview session_id: 5037d3bfa31 version: 1.54.0-SNAPSHOT-11881644 ROOT.src.Company.Departments:91...ROOT.src.Core.Database:263...ROOT.src.Core.Statistics:390: Memory usage: 7.63MB (8.00MB real), max 7.83MB (8.00MB real)\n" + "lu2-pre-sm-swap-manager1 (192.168.236.230) 2014-07-24 14:09:27,193 [debug] PRE-BCP 213.146.188.31 [marti.us] bcp:4934846 GET 3a90f85c /members/overview session_id: 5037d3bfa31 version: 1.54.0-SNAPSHOT-11881644 ROOT.src.Company.Departments:91...ROOT.src.Core.Database:263...ROOT.src.Core.Database:513: DB CACHE GET OK (total: 0, cache: 0): bcp_departments-4934846.3903997f7fe55eb81eaa07fc5e598ba0\n" + "lu2-pre-sm-swap-manager1 (192.168.236.230) 2014-07-24 14:09:27,194 [debug] PRE-BCP 213.146.188.31 [marti.us] bcp:4934846 GET 3a90f85c /members/overview session_id: 5037d3bfa31 version: 1.54.0-SNAPSHOT-11881644 ROOT.src.Company.Departments:91...ROOT.src.Core.Database:263...ROOT.src.Service.Cache.Request:72: REQUEST CACHE SET \"bcp_departments-4934846.3903997f7fe55eb81eaa07fc5e598ba0\" : object\n" + "lu2-pre-sm-swap-manager1 (192.168.236.230) 2014-07-24 14:09:27,237 [debug] PRE-BCP 213.146.188.31 [marti.us] bcp:4934846 GET 3a90f85c /members/overview session_id: 5037d3bfa31 version: 1.54.0-SNAPSHOT-11881644 ROOT.src.Service.Feature:140: get_real_value (webtracking, skype, GB): 1\n" + "lu2-pre-sm-swap-manager1 (192.168.236.230) 2014-07-24 14:09:27,240 [debug] PRE-BCP 213.146.188.31 [marti.us] bcp:4934846 GET 3a90f85c /members/overview session_id: 5037d3bfa31 version: 1.54.0-SNAPSHOT-11881644 ROOT.src.Swap.Application2:553: serve_endpoint (members/overview): OK"; 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