Regular Expressions 101

Save & Share

Flavor

  • PCRE2 (PHP >=7.3)
  • PCRE (PHP <7.3)
  • ECMAScript (JavaScript)
  • Python
  • Golang
  • Java 8
  • .NET 7.0 (C#)
  • Rust
  • Regex Flavor Guide

Function

  • Match
  • Substitution
  • List
  • Unit Tests

Tools

Sponsors
There are currently no sponsors. Become a sponsor today!
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 = "Alarm:\\s+0:\\s+T AL:\\s+(?P<Temp_AL_0>[+-]\\d+\\.\\d+)\\,\\s+t AL:\\s+(?P<time_AL_0>\\d+)\\s+1:\\s+T AL:\\s+(?P<Temp_AL_1>[+-]\\d+\\.\\d+)\\,\\s+t AL:\\s+(?P<time_AL_1>\\d+)"; final String string = "Device: Q-tag Fridge-tag 2\n" + "Vers: 0.5\n" + "Fw Vers: 3.4p0o\n" + "Sensor: 4\n" + "Conf:\n" + " Serial: 130400141244\n" + " PCB: BG0211306532\n" + " CID: 1000\n" + " Lot: 1792_20_08\n" + " Zone: 0.00\n" + " Measurement delay: 10\n" + " Moving Avrg: 1\n" + " User Alarm Config: 0\n" + " User Clock Config: 1\n" + " Alarm Indication: 0\n" + " Temp unit: C\n" + " Alarm:\n" + " 0:\n" + " T AL: -0.5, t AL: 60\n" + " 1:\n" + " T AL: +8.3, t AL: 600\n" + " Int Sensor:\n" + " Timeout: 1, Offset: +0.0\n" + " Report history length: 60\n" + " Det Report: 3\n" + " Use ext devices: 0\n" + " Test Res: 1, Test TS: 2021-05-20 12:51\n" + "Hist:\n" + " TS Actv: 2022-03-05 11:09\n" + " TS Report Creation: 2022-03-28 07:26\n" + " 1:\n" + " Date: 2022-03-28\n" + " Min T: +3.2, TS Min T: 05:24\n" + " Max T: +3.5, TS Max T: 00:00\n" + " Avrg T: +3.3\n" + " Alarm:\n" + " 0:\n" + " t Acc: 0\n" + " 1:\n" + " t Acc: 0\n" + " Int Sensor timeout:\n" + " t AccST: 0\n" + " Events: 8\n" + " Checked:\n" + " TS AM: 07:20\n" + " 2:\n" + " Date: 2022-03-27\n" + " Min T: +2.9, TS Min T: 06:02\n" + " Max T: +3.8, TS Max T: 17:13\n" + " Avrg T: +3.2\n" + " Alarm:\n" + " 0:\n" + " t Acc: 0\n" + " 1:\n" + " t Acc: 0\n" + " Int Sensor timeout:\n" + " t AccST: 0\n" + " Events: 0\n" + " 3:\n" + " Date: 2022-03-26\n" + " Min T: +2.3, TS Min T: 01:57\n" + " Max T: +3.3, TS Max T: 16:49\n" + " Avrg T: +2.8\n" + " Alarm:\n" + " 0:\n" + " t Acc: 0\n" + " 1:\n" + " t Acc: 0\n" + " Int Sensor timeout:\n" + " t AccST: 0\n" + " Events: 0\n" + " 4:\n" + " Date: 2022-03-25\n" + " Min T: +2.1, TS Min T: 01:07\n" + " Max T: +2.8, TS Max T: 16:04\n" + " Avrg T: +2.4\n" + " Alarm:\n" + " 0:\n" + " t Acc: 0\n" + " 1:\n" + " t Acc: 0\n" + " Int Sensor timeout:\n" + " t AccST: 0\n" + " Events: 0\n" + " 5:\n" + " Date: 2022-03-24\n" + " Min T: +1.8, TS Min T: 01:35\n" + " Max T: +2.5, TS Max T: 18:48\n" + " Avrg T: +2.1\n" + " Alarm:\n" + " 0:\n" + " t Acc: 0\n" + " 1:\n" + " t Acc: 0\n" + " Int Sensor timeout:\n" + " t AccST: 0\n" + " Events: 0\n" + " 6:\n" + " Date: 2022-03-23\n" + " Min T: +1.7, TS Min T: 09:23\n" + " Max T: +2.2, TS Max T: 16:23\n" + " Avrg T: +1.9\n" + " Alarm:\n" + " 0:\n" + " t Acc: 0\n" + " 1:\n" + " t Acc: 0\n" + " Int Sensor timeout:\n" + " t AccST: 0\n" + " Events: 0\n" + " 7:\n" + " Date: 2022-03-22\n" + " Min T: +2.0, TS Min T: 06:18\n" + " Max T: +2.3, TS Max T: 00:09\n" + " Avrg T: +2.0\n" + " Alarm:\n" + " 0:\n" + " t Acc: 0\n" + " 1:\n" + " t Acc: 0\n" + " Int Sensor timeout:\n" + " t AccST: 0\n" + " Events: 0\n" + " 8:\n" + " Date: 2022-03-21\n" + " Min T: +2.2, TS Min T: 21:03\n" + " Max T: +2.8, TS Max T: 00:00\n" + " Avrg T: +2.4\n" + " Alarm:\n" + " 0:\n" + " t Acc: 0\n" + " 1:\n" + " t Acc: 0\n" + " Int Sensor timeout:\n" + " t AccST: 0\n" + " Events: 0\n" + " 9:\n" + " Date: 2022-03-20\n" + " Min T: +2.7, TS Min T: 23:40\n" + " Max T: +3.1, TS Max T: 12:47\n" + " Avrg T: +2.9\n" + " Alarm:\n" + " 0:\n" + " t Acc: 0\n" + " 1:\n" + " t Acc: 0\n" + " Int Sensor timeout:\n" + " t AccST: 0\n" + " Events: 0\n" + " 10:\n" + " Date: 2022-03-19\n" + " Min T: +3.0, TS Min T: 06:10\n" + " Max T: +4.1, TS Max T: 10:59\n" + " Avrg T: +3.2\n" + " Alarm:\n" + " 0:\n" + " t Acc: 0\n" + " 1:\n" + " t Acc: 0\n" + " Int Sensor timeout:\n" + " t AccST: 0\n" + " Events: 0\n" + " 11:\n" + " Date: 2022-03-18\n" + " Min T: +2.8, TS Min T: 05:37\n" + " Max T: +3.6, TS Max T: 16:54\n" + " Avrg T: +3.2\n" + " Alarm:\n" + " 0:\n" + " t Acc: 0\n" + " 1:\n" + " t Acc: 0\n" + " Int Sensor timeout:\n" + " t AccST: 0\n" + " Events: 0\n" + " 12:\n" + " Date: 2022-03-17\n" + " Min T: +3.1, TS Min T: 21:34\n" + " Max T: +4.6, TS Max T: 10:35\n" + " Avrg T: +3.4\n" + " Alarm:\n" + " 0:\n" + " t Acc: 0\n" + " 1:\n" + " t Acc: 0\n" + " Int Sensor timeout:\n" + " t AccST: 0\n" + " Events: 0\n" + " 13:\n" + " Date: 2022-03-16\n" + " Min T: +3.5, TS Min T: 21:44\n" + " Max T: +4.2, TS Max T: 12:21\n" + " Avrg T: +3.7\n" + " Alarm:\n" + " 0:\n" + " t Acc: 0\n" + " 1:\n" + " t Acc: 0\n" + " Int Sensor timeout:\n" + " t AccST: 0\n" + " Events: 0\n" + " 14:\n" + " Date: 2022-03-15\n" + " Min T: +3.7, TS Min T: 07:28\n" + " Max T: +5.2, TS Max T: 08:21\n" + " Avrg T: +3.9\n" + " Alarm:\n" + " 0:\n" + " t Acc: 0\n" + " 1:\n" + " t Acc: 0\n" + " Int Sensor timeout:\n" + " t AccST: 0\n" + " Events: 8\n" + " Checked:\n" + " TS AM: 08:08\n" + " 15:\n" + " Date: 2022-03-14\n" + " Min T: +4.0, TS Min T: 20:45\n" + " Max T: +5.3, TS Max T: 09:01\n" + " Avrg T: +4.2\n" + " Alarm:\n" + " 0:\n" + " t Acc: 0\n" + " 1:\n" + " t Acc: 0\n" + " Int Sensor timeout:\n" + " t AccST: 0\n" + " Events: 0\n" + " 16:\n" + " Date: 2022-03-13\n" + " Min T: +4.1, TS Min T: 11:42\n" + " Max T: +4.8, TS Max T: 01:32\n" + " Avrg T: +4.4\n" + " Alarm:\n" + " 0:\n" + " t Acc: 0\n" + " 1:\n" + " t Acc: 0\n" + " Int Sensor timeout:\n" + " t AccST: 0\n" + " Events: 0\n" + " 17:\n" + " Date: 2022-03-12\n" + " Min T: +4.1, TS Min T: 14:05\n" + " Max T: +4.9, TS Max T: 21:34\n" + " Avrg T: +4.6\n" + " Alarm:\n" + " 0:\n" + " t Acc: 0\n" + " 1:\n" + " t Acc: 0\n" + " Int Sensor timeout:\n" + " t AccST: 0\n" + " Events: 0\n" + " 18:\n" + " Date: 2022-03-11\n" + " Min T: +4.2, TS Min T: 06:22\n" + " Max T: +4.9, TS Max T: 15:38\n" + " Avrg T: +4.5\n" + " Alarm:\n" + " 0:\n" + " t Acc: 0\n" + " 1:\n" + " t Acc: 0\n" + " Int Sensor timeout:\n" + " t AccST: 0\n" + " Events: 0\n" + " 19:\n" + " Date: 2022-03-10\n" + " Min T: +3.8, TS Min T: 00:05\n" + " Max T: +5.1, TS Max T: 10:27\n" + " Avrg T: +4.1\n" + " Alarm:\n" + " 0:\n" + " t Acc: 0\n" + " 1:\n" + " t Acc: 0\n" + " Int Sensor timeout:\n" + " t AccST: 0\n" + " Events: 0\n" + " 20:\n" + " Date: 2022-03-09\n" + " Min T: +3.3, TS Min T: 06:05\n" + " Max T: +4.0, TS Max T: 12:03\n" + " Avrg T: +3.6\n" + " Alarm:\n" + " 0:\n" + " t Acc: 0\n" + " 1:\n" + " t Acc: 0\n" + " Int Sensor timeout:\n" + " t AccST: 0\n" + " Events: 0\n" + " 21:\n" + " Date: 2022-03-08\n" + " Min T: +3.3, TS Min T: 05:16\n" + " Max T: +4.1, TS Max T: 08:48\n" + " Avrg T: +3.7\n" + " Alarm:\n" + " 0:\n" + " t Acc: 0\n" + " 1:\n" + " t Acc: 0\n" + " Int Sensor timeout:\n" + " t AccST: 0\n" + " Events: 8\n" + " Checked:\n" + " TS AM: 08:36\n" + " 22:\n" + " Date: 2022-03-07\n" + " Min T: +3.7, TS Min T: 23:41\n" + " Max T: +4.5, TS Max T: 00:00\n" + " Avrg T: +4.1\n" + " Alarm:\n" + " 0:\n" + " t Acc: 0\n" + " 1:\n" + " t Acc: 0\n" + " Int Sensor timeout:\n" + " t AccST: 0\n" + " Events: 0\n" + " 23:\n" + " Date: 2022-03-06\n" + " Min T: +4.0, TS Min T: 04:03\n" + " Max T: +7.1, TS Max T: 08:54\n" + " Avrg T: +4.5\n" + " Alarm:\n" + " 0:\n" + " t Acc: 0\n" + " 1:\n" + " t Acc: 0\n" + " Int Sensor timeout:\n" + " t AccST: 0\n" + " Events: 8\n" + " Checked:\n" + " TS AM: 08:43\n" + " 24:\n" + " Date: 2022-03-05\n" + " Min T: +4.3, TS Min T: 23:23\n" + " Max T: +14.9, TS Max T: 11:23\n" + " Avrg T: +5.0\n" + " Alarm:\n" + " 0:\n" + " t Acc: 0\n" + " 1:\n" + " t Acc: 31\n" + " Int Sensor timeout:\n" + " t AccST: 0\n" + " Events: 24\n" + " Checked:\n" + " TS AM: 11:09\n" + " TS PM: 12:45\n" + "Cert:\n" + " Vers: 1.0\n" + " Lot: 1792_20_08\n" + " Issuer: Berlinger & Co. AG\n" + " Valid from: 2020-08-21 07:39\n" + " Owner: Berlinger & Co. AG\n" + " Public Key: d73cd26b379bd0a250d98498e15c739ab53594e9768b247a0713637cba30e474b4fcc1aae45f30ec7cc878c102cf9648d775670d2f93b48726a0f21d3ca71074\n" + "Sig Cert: 6eef7b154b51a1f4a4186e76b495d43dc25cedbaab8b18486895df5d773530795679b8aa3678e511e45e28cb894bcc051dd90d13f19f699c4f42b46c4ed5d621\n" + "Sig: ec3ca65a802abce36aacf3e12679075acf05c8f55586e79c16a489c59ac4f3b975f34b4d1596a2083a31b1f6172bcca388463a95e4f2ed63bdc5808433fb6820\n"; 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